一类线性切换系统H∞状态反馈控制:LMI方法

研究一共由任意有限多个线性子系统组成的切换系统的H∞状态反馈控制问题．利用Lyapunov函数方法，给出由线性矩阵不等式（LMI）表示的控制器存在的充分条件，并设计了相应的子控制器和切换策略．最后给出一个数值仿真实例，证明了所得结论的有效性．     

时滞切换系统动态反馈H∞控制

对于由若干线性时滞子系统构成的切换系统,考虑了动态反馈控制与切换策略的设计,以实现H∞性能的优化．利用其连续性不受切换行为影响的Lyapunov-Krasovskii泛函构造方式,并结合闭环子系统的适当变换,导出了与时滞相关的控制器及切换策略的存在性判据．通过参数代换与矩阵相似变换,将此判据等价地转化为线性矩阵不等式,从而解得泛函与控制器参数．仿真结果验证了方法的有效性．     

基于模糊逻辑技术的切换策略

下一代宽带无线通信网在为用户提供高速率语音服务以及图像、视频信息的传输和高速接入Internet服务等丰富的业务类型的同时,也给系统的切换策略带来新的挑战。以往仅考虑单一因素对系统影响的切换策略已不适用于具有丰富业务类型的下一代宽带无线通信网络。该文利用模糊逻辑技术进行切换过程中的目标小区选取。相比传统方案,模糊逻辑技术可以兼顾多种因素,使得选取结果更加合理,并且可以均衡系统负载、减少切换的拒绝率。     

时滞切换系统动态反馈H∞控制

对于由若干线性时滞子系统构成的切换系统, 考虑了动态反馈控制与切换策略的设计, 以实 现H-infinity性能的优化. 利用其连续性不受切换行为影响的Lyapunov-Krasovskii泛函构造方式, 并结合闭环子系统的适当变换, 导出了与时滞相关的控制器及切换策略的存在性判据.通过参数代换与矩阵 相似变换, 将此判据等价地转化为线性矩阵不等式, 从而解得泛函与控制器参数. 仿真结果验证了方法的有 效性.     

具有边界切换反馈控制的波方程网络及其稳定性分析

本文主要就具有两种不同切换反馈控制的网络系统进行探讨.该系统是由波方程所描述的二叉树结构,其中,系统的一端固定,另外两端分别施加弹性反馈控制α(t)υ_(2t)(x,t),β(t)υ_(3t)(x,t),并且α(t),β(t)都是以2T为周期的Heaviside型函数.考虑两种情况下闭环系统的稳定性:一种是两个切换控制同时开同时关的情况,一种是两个控制器不同时开关的情况,即在任意的时间段只有一个控制器在工作.本文利用达朗贝尔方法给出闭环系统的具体的解的表达式,然后通过迭代方法对产生的迭代矩阵进行谱分析,由此得到系统的解的性质,从而得到了系统的指数稳定性和衰减速率.     

切换状态反馈控制系统的稳定性分析

研究了一类切换控制系统的稳定性分析问题,切换控制器由多个线性状态反馈控制器组成。运用Lyapunov方法得出了稳定性的时域判据,通过求解一个线性矩阵不等式的方法分析切换控制系统的稳定性,利用KYP引理得到了等价的频域判据;并且研究了一类含有参数不确定性的切换控制系统的鲁棒稳定性分析问题,给出了稳定性时域判据和频域判据。稳定性分析的主要结果是基于公共二次Lyapunov函数的,适用于切换系统任意切换的情形,该方法在工程实例中的应用表明了其有效性。     

一类切换模糊时滞系统的状态反馈控制

针对切换模糊时滞系统,根据平行分布补偿算法,设计了模糊状态反馈控制器.使用切换技术及单Lyapunov函数和多Lyapunov函数方法,给出了这一类切换模糊时滞系统渐近稳定的充分条件及切换律.仿真结果表明了方法的有效性.     

切换广义系统的H∞输出反馈控制

针对一类切换广义系统,提出了一种更加简单易解的H∞输出反馈控制方法.基于投影引理和Finsler's引理结合线性矩阵不等式技术,给出保证闭环系统在输出反馈控制下是容许的并具有期望的H∞性能水平的严格线性矩阵不等式条件.所提出的充分条件不要求对系统模型进行坐标变换,也不需要对Lyapunov矩阵和其逆矩阵进行分解.给出的结果可经例子进行验证并可以推广到单一的广义系统和正常的切换系统.     

实时离散事件系统的动态反馈控制

本文研究了一类含确定性状态时间的实时离散事件系统的动态反馈控制问题.基于一定语言的实时可控性的概念,证明了对给定实时离散事件系统G,存在完备监控器φ使L(φ/Gr)=K的充分必要条件是K是闭及实时可控的,并得到了有关实时监控问题解存在的充要条件.     

基于观测器的切换模糊时滞系统的反馈控制

针对状态不可测的切换模糊时滞系统, 根据平行分布补偿算法(PDC), 设计了切换模糊观测器和反馈控制器, 应用共同Lyapunov函数方法使观测误差系统在任意切换下渐近稳定, 应用多Lyapunov函数方法, 使系统状态在设计切换律下渐近稳定, 并给出了时滞相关的切换模糊系统渐近稳定的矩阵不等式条件. 仿真结果表明结论的有效性.     

不确定时滞系统的无记忆鲁棒控制

讨论了含有时变时滞以及时变输入控制的 时滞线性系统的鲁棒可镇定性问题,就所有可结构化不确定参数以及所有非结构化不确定参 数两种情形分别得到了系统可由状态反馈控制器镇定的充分条件,并且相应给出了控制器的 设计．     

ECOLOGICAL SYSTEMS CONTROL BY FUZZY LOGIC CONTROLLER

The application of fuzzy logic control in the long‐term management of an ecological system is proposed. The ecological systems are subject to unpredictable but bounded disturbances due to changes in climatic conditions, disease, migrating species, etc. By applying the fuzzy logic controller, the biomasses of exploited and continually disturbed ecological systems will converge in a comparatively short time and keep the biomasses within a small neighborhood of the unique nontrivial optimal equilibrium state of the undisturbed exploited ecosystem. Demonstration through examples reveals that the accumulated yield with fuzzy logic control is better than that with state feedback control or no control.     

MODEL-BASED FUZZY LOGIC CONTROL OF A NONLINEAR PLANT

A full-envelope controller for nonlinear systems is developed based on a novel model-based fuzzy logic control (MBFLC) approach. This approach envisages a bank of linear compensators, with each compensator optimized for a different operating point throughout the operational envelope. The fuzzy logic module properly blends the compensator outputs into a composite control signal, and avoids instability when none of the individual compensators are valid. In general practice, in the strongly nonlinear system under consideration, the fuzzy element of the MBFLC dominates due to the extremely small regions of validity of perturbation models of the strongly nonlinear plant. The MBFLC, with the composite control input smoothed by a linear compensator, provides full-envelope control of the benchmark plant. © 1997 by John Wiley & Sons, Ltd. This paper was produced under the auspices of the US Government and it is therefore not subject to copyright in the US.     

ANALYSIS AND DESIGN OF FEEDBACK CONTROL SYSTEMS WITH TRACKING ERRORS SQUARE

In this study, a command tracking error square control scheme is first proposed for analysis and design of feedback control systems. One of the tracking errors is low‐pass filtered and used in the feedback loop for gain adaptation; the other is used in the forward loop for command tracking control. The overall systems are nonlinear feedback systems, and can be reconfigured to an automatic gain control (AGC) loop with command tracking error input. The stability and robustness of the controlled systems are verified by time response, frequency response, and large parameter variation testing with a simple illustrating example and are finally applied to a complicated electro‐hydraulic velocity servo system with large load disturbance.     

控制模态转移型系统的稳定切换

离散事件决策子系统和数值反馈子系统合成的混合控制系统呈现出复杂的稳定动态特性.研究了在达到模态切换周期的控制规则下,相应的系统连续状态轨迹的平稳性.给出了具有较少约束的李雅谱诺夫型判据,不要求全局一致的李雅谱诺夫函数,不要求每个模态下的能量函数单调递减.     

OPTIMAL FEEDBACK CONTROL OF SISO SATURATION SYSTEMS OVER A CLASS OF NONLINEAR STABILIZING CONTROLLERS

This paper focuses on the feedback control of a linear single-input single-output process in the presence of input saturation constraints. First, closed-loop stability is guaranteed through the use of a parametrization of all nonlinear stabilizing controllers in terms of an S-stable parameter Q. Then, a performance measure is proposed that quantifies closed-loop performance with respect to a finite number of disturbances. Subsequently, the best achievable performance is quantified over a class of nonlinear stabilizing controllers parametrized in terms of absolutely summable second order Volterra operators. The resulting computational procedure involves the solution of a sequence of MILP's. An illustrative example is employed to demonstrate the proposed procedure. This example establishes that, for this performance measure, there may exist a value of the saturation bound for which the best achievable control system performance of the saturating system is strictly better than the corresponding best achievable linear performance. The same example also demonstrates that nonlinear control can perform strictly better than linear control for a performance measure that employs a finite number of disturbances. © 1997 by John Wiley & Sons, Ltd. Int. J. Robust Nonlinear Control, Vol. 7, 449–474 (1997).     

非完整链式系统的输出跟踪控制 ——动态扩展线性化方法1)

Tracking control of nonholonomic single and multi-chained systems is investigated in this paper.It is shown that the nonholonomic chained systems can be completely linearized by dynamic feedback linearization if the proper output variables are chosen and certain conditions are satisfied,and linear tracking controllers can then be designed for the resulted linearized systems.As an example,a moving cart is simulated to verify the proposed strategy.     

非完整链式系统的输出跟踪控制--动态扩展线性化方法

针对非完整单链和多链系统,利用动态反馈线性化技术设计了输出跟踪控制器.证明了当满足一定的条件时,通过选择适当的输出变量并利用动态反馈可使非完整链式系统实现输入-输出完全线性化,从而可设计线性控制器跟踪期望的运动轨迹.最后以移动小车的跟踪控制为例,通过仿真验证了文中方法的有效性.     

一般非线性系统的控制解耦

本文利用微分几何方法,讨论了一般非线性系统的反馈解耦和无交互控制问题,给出了一般非线性系统的状态方程反馈解耦及块输入-块输出无交互控制问题可解的充分必要条件.