线性不确定广义时滞系统的鲁棒无源滤波器设计

研究一类线性不确定广义时滞系统的鲁棒无源滤波器设计问题．系统中所含的不确定性假设是未知且范数有界的．利用线性矩阵不等式方法和Lyapunov函数方法相结合，给出了广义滤波增广系统时滞独立的鲁棒无源滤波器的存在条件．设计目标是对所有的不确定性，滤波增广系统是正则、稳定、无脉冲的，且满足所提的无源滤波性能指标．所提的滤波器设计问题可转化为标准的线性矩阵不等式的求解问题，并可推广到多时滞情况．数值例子验证了设计方法的可行性．     

线性广义系统的无源控制

考察了线性广义系统的无源性控制问题．一方面，利用微分几何方法，给出了广义系统无源的充分必要条件;另一方面，将存储函数具体化，利用线性矩阵不等式，推出了广义系统无源的充分条件．最后，基于这两个方面得到存在状态反馈且使闭环系统无源和严格无源的条件．     

微分代数系统的无源性

考察了微分代数系统的无源性的控制问题.提出了微分代数系统无源的定义以及KYP特性的定义.利用类似微分几何理论的方法,通过引入微分代数系统的M导数,推出了微分代数系统无源与KYP特性等价的定理和微分代数系统无源性的充分必要条件.最后给出了无源控制器存在的条件.M导数的方法可以看作是L导数方法的延伸.本文所获得的一系列结果,使来自于物理系统的无源概念与控制理论有机结合起来.     

至少有一个增长无源的子系统切换非线性系统的输出跟踪控制

本文利用平均驻留时间方法解决至少有一个增长无源的子系统的切换非线性系统的输出跟踪问题.对于给定的无源率,设计子系统控制器使得平均驻留时间变小.所得到的平均驻留时间依赖于增长无源子系统的增长指数小时间范数可观性.最后,通过数值例子验证所提出方法的有效性.     

不确定离散广义系统的时滞相关非脆弱无源控制

针对不确定离散时滞广义系统，研究其时滞相关鲁棒严格无源、渐近稳定性以及相关的非脆弱控制问题．首先利用线性矩阵不等式（LMI）和自由权矩阵的概念，分析了离散广义系统时滞相关严格无源以及渐近稳定性的条件；然后讨论不确定离散广义系统的时滞相关鲁棒严格无源和渐近稳定性，并讨论具有加性非脆弱反馈控制设计使得闭环系统满足相应性能，同时给出控制器的构造方法；最后通过数值算例说明该方法的有效性．     

时滞T-S模糊系统的无源控制器设计

针对时滞T-S模糊系统, 给出了使得系统无源的状态反馈控制器存在的充分条件, 与现有结果相比保守性更小. 在此基础上, 给出了基于观测器的无源控制器与动态输出反馈无源控制器存在的充分条件. 控制器的设计方法都归结为求解一组线性矩阵不等式(Linear matrix inequality, LMI). 最后通过仿真例子, 说明所给设计方法的有效性.     

基于泰勒级数的迭代学习算法

针对存在不确定扰动的线性时变系统的轨迹跟踪控制问题,提出了基于泰勒级数的迭代学习算法．该算法利用泰勒级数将系统参数化,导出一种基于泰勒级数的线性时变系统的近似模型．在此模型的基础上,利用迭代学习方式修正输入量的泰勒展开系数,并用LMI方法求解学习增益矩阵．所提出算法在系统不满足正则性或无源性时,仍可用输出误差信号来构造学习律．仿真结果表明了该算法的有效性．     

时变不确定广义系统的鲁棒无源控制

研究了除E外其余系数矩阵均含有范数有界时变不确定性的广义系统的鲁棒无源控制器设计问题.利用线性矩阵不等式方法,首先给出自治系统广义二次稳定且无源的充分条件;然后给出状态反馈鲁棒无源控制器的存在条件并用线性矩阵不等式的解构造了相应的控制器;随后以矩阵不等式的形式得到了动态输出反馈鲁棒无源控制器的存在条件,同时利用矩阵不等式的解给出相应控制器的设计方法;最后举例说明了所提出方法的可行性.     

线性广义系统的鲁棒无源控制

考察了线性广义系统的无源性的控制问题和鲁棒无源的控制问题,使来自于物理系统的无源概念与控制理论有机结合起来.一方面,利用微分几何方法,给出了广义系统无源的充分必要条件;另一方面,将存储函数具体化,利用矩阵不等式,推出了广义系统鲁棒无源的充分条件.     

基于输出严格无源的切换非线性系统的H∞ 分析

针对切换非线性系统,考虑了基于输出严格无源性的 ∞问题.利用每个子系统的输出严格无源性(这里并不要求每个子系统都在整个时间域上满足输出严格无源性,只要求子系统在其激活时间段内满足输出严格无源性),同时借助切换系统理论中的多 Lyapunov 函数方法,用输出严格无源性中的存储函数作为备选的多 Lyapunov 函数,设计了依赖存储函数的最小切换规则,研究了一类切换非线性系统的 ∞问题,给出了存在 ∞性能指标的充分条件.此外,这种基于输出严格无源性的方法也可用于分析切换级联系统的 ∞问题.最后,通过仿真算例验证了这种基于输出严格无源性的方法的有效性.     

遥操作系统力觉接口的无源性设计

力觉接口是指人和遥操作机械手之间的接口,用来给操作人员提供操作时的一种虚拟环境．无源性是这种接口系统设计的主要要求,但是前人得出的无源性条件过于保守．本文从采样控制系统的频率特性出发推导了一个没有保守性的接口系统无源性的条件．文中并指出无源性只是接口的一个属性,要正确设计还需考虑到伺服设计的一些基本要求,诸如系统的带宽、阻尼等．文中还结合例子给出了接口系统无源性设计的步骤．     

Passivity,Feedback Equivalence and Global Stabilization of Nonlinear Markovian Jump Systems

This paper combines the passivity theory with geometric control theory for nonlinear Markovian jump systems. The key point concentrates on taking the appropriate coordinate changes following with the Markovian switchings. Based on this concept, we investigate the passivity, feedback equivalence and global stabilization problems, which implies that under a proposed strongly minimum‐phase condition, the nonlinear Markovian jump system is feedback equivalent to a passive system. A numerical example is presented to illustrate the effectiveness of our results.     

Nonlinear controls for a class of discrete‐time bilinear systems

For a discrete‐time neutrally stable bilinear system, a nonlinear state feedback control based on the passivity design has been proposed to stabilize the system globally and asymptotically. This paper shows that the decay rate resulting from the passivity control is not exponential, and the system's response speed becomes very sluggish asymptotically. A ‘normalized’ nonlinear control is therefore proposed to achieve exponential stability. The new exponentially stabilizing control not only improves the system's response speed, but also enhances the system's robustness against small parametric perturbations. Copyright © 2003 John Wiley & Sons, Ltd.     

基于自适应无源化的蔡氏电路混沌同步

根据蔡氏电路混沌系统的特点,得出了蔡氏电路混沌驱动系统与响应系统的误差系统.根据混沌系统的同步条件,可将混沌的同步问题转化成为误差系统的稳定性问题,即使混沌同步误差系统渐近稳定以实现混沌同步控制.针对蔡氏电路混沌系统的误差系统,采用自适应无源化方法,设计了使同步误差系统渐近稳定的具有自适应功能的反馈镇定器.该控制方法实现了2个蔡氏电路混沌系统同步,仿真研究验证了该方法的有效性.     

Passivity‐based sliding mode controller/observer for second‐order nonlinear systems

A passivity‐based sliding mode control for a class of second‐order nonlinear systems with matched disturbances is proposed in this paper. Firstly, a nonlinear sliding surface is designed using feedback passification, in which the passivity is employed to guarantee the closed‐loop system's stability. The passivity‐based controller comprising a discontinuous term guarantees globally asymptotical convergence to the sliding surface. A sliding mode‐based control law that satisfies the reaching and sliding condition is also developed. Moreover, the passivity‐based sliding mode observer is also developed to effectively estimate the system states. Compared with conventional sliding mode control, the proposed control scheme has a shorter reaching time; and hence, the system performance is less affected by disturbances, thus eliminating the need to increase the control input gain. Finally, simulation results demonstrate the validity of the proposed method.     

Process systems and passivity via the Clausius-Planck inequality

In this paper we define a process system to be a system which has actions with the Clausius-Planck and conservation properties. We use standard and well established results derived from macroscopic thermodynamics to show that a process system has actions which satisfy the dissipation inequality. Furthermore, these actions have an inner product structure and a link between the thermodynamic theory of process systems and the input-output passivity theory of nonlinear control is established. The paper therefore represents a step towards developing a passivity based approach for distributed control system design for chemical processes. A review of relevant concepts from thermodynamics is given in an appendix.     

Passivity-based Visual Motion Observer with Panoramic Camera for Pose Control

This paper considers the vision-based estimation and pose control with a panoramic camera via passivity approach. First, a hyperbolic projection of a panoramic camera is presented. Next, using standard body-attached coordinate frames (the world frame, mirror frame, camera frame and object frame), we represent the body velocity of the relative rigid body motion (position and orientation). After that, we propose a visual motion observer to estimate the relative rigid body motion from the measured camera data. We show that the estimation error system with a panoramic camera has the passivity which allows us to prove stability in the sense of Lyapunov. The visual motion error system which consists of the estimation error system and the pose control error system preserves the passivity. After that, stability and L ₂-gain performance analysis for the closed-loop system are discussed via Lyapunov method and dissipative systems theory, respectively. Finally, simulation and experimental results are shown in order to confirm the proposed method.     

Reset passivation of nonlinear controllers via a suitable time-regular reset map

For a class of square continuous-time nonlinear controllers we design a suitable resetting rule inspired by the resetting rule for Clegg integrators and First Order Reset Elements (FORE). With this rule, we prove that the arising hybrid system with temporal regularization is passive in the conventional continuous-time sense with a small shortage of input passivity decreasing with the temporal regularization constant. Based on the passivity property, we then investigate the finite gain stability of the interconnection between this passive controller and a passive nonlinear plant.     

时滞关联大系统基于分散控制的无源性

无源性不仅是系统的一个重要性质,而且是控制一个系统的重要途径.本文基于分散控制方法研究了关联大系统的无源性.利用Lyapunov-Krasovskii泛函方法和Hamilton函数方法,通过求解线性矩阵不等式(LMIs)得到了分散无源控制器的显式表达.所得到的新的无源性判据和无源控制器的参数是与时滞相关的.当关联时滞已知时,这些新结果的条件易于用Matlab中的LMI工具箱进行验证,因而控制器的设计也容易实现.最后用数值例子说明了所得到定理的有效性和无源控制器的设计过程.     

微手系统的鲁棒无源跟踪控制

近年来, 微手系统作为机器人技术的一个热门研究领域, 受到了越来越多的关注. 由于微手系统是复杂且具有非线性的, 因此在实际应用当中很难达到精确跟踪的性能. 为了解决微手系统的精准控制问题, 本文讨论了微手系统的鲁棒无源跟踪控制. 首先, 运用基于演算子理论的鲁棒右互质分解方法, 建立了微手系统的动态模型. 然后, 通过结合无源补偿算子, 设计了无源鲁棒控制器, 保证了系统的鲁棒稳定性和无源性. 进而提出了基于双Bezout恒等式的鲁棒跟踪控制方案, 使整个非线性系统具有较强的鲁棒性和良好的跟踪性能. 最后, 通过仿真进一步验证了所提出方法的有效性