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1.
时滞切换系统的时滞依赖稳定   总被引:2,自引:1,他引:1  
首先利用多Lyapunov 函数方法, 分析常时滞切换系统的时滞依赖稳定性, 并给出此系统时滞依赖稳定的充分条件及切换律的设计; 然后运用共同Lyapunov 函数方法, 研究一类时变时滞切换系统的时滞依赖稳定性, 也给出此系统时滞依赖稳定的充分条件及切换律的设计. 所得结果均可用线性矩阵不等式方法求解. 最后通过仿真验证了结论的正确有效性.  相似文献   

2.
谭永红 《测控技术》2003,22(9):48-50
对具有时变时滞的非线性动态系统进行时滞估计是系统辩识的一项重要课题。为估计系统的动态特性,采用了一种带外反馈的动态神经网络。如果时滞是时变的,需要研究在线时滞估计机构来跟踪时滞的变化。本提出了两种分别称之为直接和间接时滞在线估计方法,其中间接法将时滞估计看作非线性优化问题,而直接法则用神经网络构造时滞估计器来跟踪时滞的变化。最后本给出了仿真的例子。  相似文献   

3.
对存在状态时滞的线性时滞系统,给出符合分离性原理的动态输出反馈控制器形式,当时滞参数不能精确已知时,给出基于观测器的关于时滞参数的自适应动态输出反馈控制器设计方案,通过求解两个相应的Riccati型矩阵不等式即可求得满足设计要求的动态输出反馈控制器及关于时滞参数的自适应律,且控制器的存在性与时滞参数精确已知时相同.最后给出了一个应用仿真示例.  相似文献   

4.
具有分数时滞的大林数字控制算法   总被引:2,自引:0,他引:2  
陈家祺 《信息与控制》1992,21(6):353-358
本文提出了基于分数时滞概念的大林(Dahlin)数字控制算法,解决了大林算法的分数时滞控制问题。通过引入分数时滞整定参数γ,实现了不稳定逆系统的控制,这不仅可以准确地描述纯时滞过程,而且可将高阶过程合理地简化为低阶分数时滞模型,提高了系统的控制品质。文中给出了仿真例子和在发动机台架冷却系统中的应用,对所得的结论进行了验证。  相似文献   

5.
线性时滞系统对时滞参数的自适应控制   总被引:10,自引:0,他引:10  
针对实际中线性时滞系统的时滞常数往往不能精确已知的缺点,对具有状态滞后的线性时滞系统提出一种对时滞常数的自适应控制方案,其控制器存在的充分条件由一个线性矩阵不等式(LMI)的形式给出,并对整个闭环系统的稳定性进行了分析。  相似文献   

6.
不确定线性多时变时滞系统的时滞相关鲁棒控制   总被引:16,自引:1,他引:16       下载免费PDF全文
张先明  吴敏  何勇 《控制与决策》2004,19(5):496-500
提出一种积分不等式新方法,讨论不确定线性多时变时滞系统的鲁棒稳定性以及鲁棒稳定化问题,首先利用Park不等式建立了基于二次型项的积分不等式,利用这一不等式获得了系统基于LMI的时滞相关、时滞导数相关鲁棒稳定条件;然后利用这一条件给出了时滞状态反馈控制器的一种新的设计方法,数值例子说明了所得结论具有较小的保守性。  相似文献   

7.
具有多个时变时滞的不确定系统的时滞相关稳定性   总被引:1,自引:0,他引:1  
研究了具有多个时变时滞的不确定系统的 稳定性问题, 利用Razumikhn定理与向量不等式的方法, 给出了不确定时滞系统稳定的充分 条件. 所得的条件与时滞相关, 在很大程度上降低了现有结果的保守性. 文末给出了一个应 用的算例, 并与已有的结果作了比较.  相似文献   

8.
具有多个未知常时滞线性系统的时滞无关稳定性   总被引:7,自引:0,他引:7  
本文针对线性时滞系统包括时滞在系统建立了时滞无关的稳定性判据,所考虑的时滞可以是多任意未知常时滞,故所得结果是对滞无关的,针对线性时滞大系统的一个说明例子比较证明了所建立的结果好于文献中存在的结果。  相似文献   

9.
文章研究了线性不确定时滞系统的时滞相关反馈镇定问题。基于系统的状态反馈给出系统可反馈镇定的控制规律。利用线性矩阵不等式(LMI)给出了系统可反馈镇定的充分条件,最后用实例验证了所得结论的正确性。  相似文献   

10.
陈兵  周玉成 《控制与决策》2004,19(9):1022-1025
研究一类用T—S模糊模型描述的非线性不确定时滞系统的时滞相关鲁棒镇定问题.基于线性矩阵不等式的可行解,首先给出利用T—S模糊模型描述的非线性时滞系统时滞相关稳定性准则;然后给出了经状态反馈鲁棒镇定设计的新方法.所设计的控制器能确保闭环系统渐近稳定.  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.  相似文献   

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