广义系统输出反馈严格正实控制器设计

研究连续广义系统的正实控制问题。目的是设计静态输出反馈和动态输出反馈严格正实控制器使得闭环系统容许且扩展严格正实。基于广义系统严格正实引理，利用线性矩阵不等式和广义代数Riccati不等式，给出了广义系统静态输出反馈和动态输出反馈严格正实控制器存在的充要条件及设计方法。对动态输出反馈情形，给出了一个数值算例说明控制器设计方法的有效性及可行性。     

On the static output feedback stabilisation of discrete event dynamic systems based upon the approach of semi-tensor product of matrices

In this paper, the static output feedback stabilisation of discrete event dynamic systems (DEDSs) is investigated via the semi-tensor product (STP) of matrices. Firstly, the dynamics of DEDSs modelled by deterministic Moore-type finite automata are converted into an matrix expression in the STP frame. Secondly, necessary and sufficient conditions for the existence of a static output feedback control pattern, stabilising the controlled discrete event dynamic systems to some equilibrium point, are given, and constructive algorithms to seek the static output feedback control pattern including an effective specific solution algorithm and an analytic solution algorithm are proposed. Thirdly, the equilibrium-based static output feedback stabilisation of DEDSs is extended to the set-based static output feedback stabilisation and necessary and sufficient conditions and constructive algorithms to seek the corresponding control pattern are provided. Finally, some examples are presented to illustrate the effectiveness of the proposed approach.     

The optimal projection equations for static and dynamic output feedback: The singular case

Oblique projections have been shown to arise naturally in both static and dynamic optimal design problems. For static controllers an oblique projection was inherent in the early work of Levine and Athans, while for dynamic controllers an oblique projection was developed by Hyland and Bernstein. This note is motivated by the following natural question: What is the relationship between the oblique projection arising in optimal static output feedback and the oblique projection arising in optimal fixed-order dynamic compensation? We show that in nonstrictly proper optimal output feedback there are, indeed, three distinct oblique projections corresponding to singular measurement noise, singular control weighting, and reduced compensator order. Moreover, we unify the Levine-Athans and Hyland-Bernstein approaches by rederiving the optimal projection equations for combined static/dynamic (nonstrictly proper) output feedback in a form which clearly illustrates the role of the three projections in characterizing the optimal feedback gains. Even when the dynamic component of the nonstrictly proper controller is of full order, the controller is characterized by four matrix equations which generalize the standard LQG result.     

机载公共设备管理系统中的自适应调度算法

多处理机任务分配和调度是机载公共设备综合管理系统中的一个关键技术问题。采用全局调度、局部调度和反馈调度相结合的方法,实现不确定性情况下的混合任务动态调度。通过改进免疫克隆算法进行静态调度,静态调度的结果作为动态分配的初始值,动态调度具有检测、分类、自适应反馈功能,适合混合任务共存以及变化的任务负载。     

Stabilization of Hamiltonian systems with dissipation

Stabilization of generalized Hamiltonian systems with dissipation is investigated. First, we generalize the Casimir submanifold approach with constant controls to the static state feedback control case. Secondly, a direct Hamiltonian function method is proposed and it is shown that this method is equivalent to the Casimir sub-manifold approach. Furthermore, a dynamic state feedback control is proposed. Some sufficient conditions and a constructive process for determining controllers are provided. It is shown that the dynamic state feedback control is more powerful than the static one. Finally, the problem of a dissipative type realization of the general controlled Hamiltonian system is discussed.     

Input-output feedback linearization of time-delay systems

In this note, the input-output linearization problem (IOLP) for a class of single-input-single-output nonlinear systems with multiple delays in the input, the output, and the state is studied. The problem is solved by means of various static or dynamic compensators, including state and output feedback. The mathematical setting is based on some noncommutative algebraic tools and the introduction of a nonlinear version of the so-called Roesser models for this class of systems. These are claimed to be the cornerstones for studying nonlinear time-delay systems. Necessary and sufficient conditions are given for the existence of a static or pure shift output feedback which solves the IOLP. Sufficient conditions for the existence of a dynamic state feedback solution are included as well.     

Static reachability and static decoupling of linear time-invariantsystems

The geometric concepts of holdability and static reachability for time-invariant linear multivariable systems are introduced. The geometric structure of multivariable linear systems are analyzed with respect to these concepts. The problem of static decoupling by dynamic feedback is defined, and the necessary and sufficient conditions for its solution for square systems is found to be a generalization of Wolowich's (1973) results on the same problem with state feedback. It is shown that the concept of static reachability is the key one in this problem's solution     

Disturbance decoupling by measurement feedback for SISO nonlinearsystems

The measurement feedback disturbance decoupling problem of nonlinear systems with single-input/single-output and single measurement is considered in this paper. Necessary and sufficient conditions are given for disturbance decoupling by static measurement feedback. New necessary conditions and sufficient conditions are presented for disturbance decoupling by dynamic measurement feedback     

模糊不确定时滞系统的静态输出的反馈镇定:迭代线性矩阵不等式方法

对一类不确定非线性时滞系统利用模糊T＿S模型进行建模,研究了静态输出反馈镇定问题.用矩阵不等式的形式给出了模糊T＿S不确定时滞系统可通过静态输出反馈镇定的充分条件.并将矩阵不等式的条件转化为迭代线性矩阵不等式(ILMI),并给出相应的算法.     

Stability of linear systems with periodic feedback and sampled-data systems

A linear multivariable time-invariant system with three periodic state feedback strategies—dynamic, static, and of the instantaneous state—is considered. For each of these feedback strategies the stability question of an appropriate closed-loop system in relation to its dependence upon the repetition frequency is examined. The proposed approach to the question is based on exponential matrix representations of the dynamics of the considered closed-loop systems. It is shown that at sufficiently large values of the repetition frequency the stability question may be decided on the basis of the stability of a certain matrix which is common for all the considered feedback strategies. It is also shown that peculiar to discrete-time control, the dead-beat stability phenomenon may appear only for a dynamic or static feedback strategy and it may be achieved when the repetition frequency is small enough. The proposed approach results in some new characterization of the stability property for multivariable sampled-data systems.     

Structure invariance for uncertain nonlinear systems

A unified study of three control problems associated to multi-input multi-output nonlinear systems with uncertainties is presented, namely, input-state linearization by static state feedback, input-output decoupling by static state feedback and input-output decoupling by dynamic compensation. For each of these problems, geometric conditions which describe intrinsic structural invariance properties are given     

Comments on the stabilization of nonlinear systems by adding anintegrator

We present a new proof of the result that static stabilizability implies dynamic stabilizability. The goal is to show how to compute explicitly the stabilizing feedback in some cases when the classical proof shows only the existence. New results on dynamic feedback stabilization are proposed     

Feedback types and users’ behavior in online innovation contests: Evidence of two underlying mechanisms

Online innovation contests (OIC) provide companies, via a dedicated community, an important means to access remote knowledge and ideas of users and thereby a creative playground for fueling innovation. Our literature review shows that our understanding of the impact of diverse types of feedback on user participation, especially continued participation, and success in OIC is at a nascent stage. The present study therefore seeks to examine why and how different types of feedback influence users’ behavior in OIC, and the detailed mechanisms underlying such influences. While our results do not show a significant relationship between receiving peer dynamic feedback and user success, we find that receiving sponsor static feedback in users’ first submission is positively associated with their continued participation in OIC. Also, when compared to peer dynamic feedback, sponsor static feedback has a stronger effect on users’ continued participation. Our goal is to confer a holistic picture of how the timing, source, and form of feedback shape user continuous participation and success in OIC.     

具有时变不确定性的线性时滞系统的鲁棒H∞控制

研究具有一般形式的不确定线性时滞系统的鲁棒H∞状态反馈控制器设计问题.基 于二次H∞性能概念,首先证明了若存在鲁棒H∞动态状态反馈控制器,则必存在鲁棒H∞静 态状态反馈控制器,然后利用线性矩阵不等式给出了鲁棒H∞静态状态反馈控制器存在的充 分条件和构造方法,最后给出一个算例验证本文方法的有效性.     

Robustness of dynamic output feedback control for singular perturbation systems

The problem of the robustness of dynamic output feedback control for singular perturbation systems is investigated. The solution to this problem is reduced to the simultaneous design of static output feedback controllers for the fast subsystem and the so-called auxiliary system of the slow subsystem. Some conditions are proposed to ensure the robustness of the actual closed-loop system. The exact upper bound of the parasitic parameter for the controlled system is also determined. Finally, an actual model which failed in dynamic output feedback control in [4] is reexamined successfully here.     

Spacecraft attitude control using magnetic actuators

The problem of inertial pointing for a spacecraft with magnetic actuators is addressed and an almost global solution to the problem is obtained by means of static attitude and rate feedback. A local solution based on dynamic attitude feedback is also presented. Simulation results demonstrate the practical applicability of the proposed approach.     

Robust adaptive sampled-data control of a class of systems understructured nonlinear perturbations

A robust adaptive sampled-data feedback stabilization scheme is presented for a class of systems with nonlinear additive perturbations. The proposed controller generates a control input by using high-gain static or dynamic feedback from nonuniform sampled values of the output. A simple adaptation rule adjusts the gain and the sampling period of the controller     

Quantized feedback control for linear uncertain systems

This paper studies robust control problems under the setting of quantized feedback. We consider both the static and dynamic logarithmic quantizers. In the static quantization case, the quantizer has an infinite number of levels, and the design problem is to find the minimal quantization density required to achieve a given control objective. In the dynamic quantization case, the problem is to minimize the number of quantization levels to achieve a given control objective. We present a number of results for different controller‐quantizer configurations. These results are developed using the so‐called sector bound approach for quantized feedback control, which was initiated by the authors previously for systems without uncertainties. Copyright © 2009 John Wiley & Sons, Ltd.     

一种状态反馈的最佳控制设计法

针对状态反馈控制设计法存在的问题,论文提出一种以时间加权的误差积分(ITE)为最优准则,并采用遗传算法寻找最佳状态反馈增益与参考输入增益,以获得系统最佳动态性能并克服了静差,这为状态反馈控制设计提供了一种新思路。仿真实验证明,文中提出的方法是有效的。