基于改进粒子群算法的模糊神经网络PID控制器设计

针对模糊神经网络PID控制器中参数初始值的设置对控制器性能影响大的问题,提出一种改进的PSO算法优化模糊神经网络PID控制器参数的设计方法.该方法采用实数编码的方式对控制器参数进行优化,并以ITAT指标作为改进的PSO优化算法的适应度函数.实验仿真表明:经过改进的PSO算法优化的模糊神经网络PID控制器具有良好的动静态性能,响应速度更快,超调量更小,控制精度更高.     

基于模糊自适应PID的无人机纵向姿态控制研究

针对无人机的典型的非线性、控制参数时变以及建模复杂的特性,设计了一种基于模糊自适应PID的控制器来实现对无人机纵向姿态的控制;该控制器以误差e和误差变化率ec作为输入,可以满足不同时刻e和ec对PID参数自整定的要求;利用模糊控制规则在线对PID参数进行修正,从而使被控对象具有更好的动、静态性能;仿真结果表明,设计的模糊自适应PID控制器具有响应快及超调小的特性,而且自适应能力也较强.     

混合模糊PID控制器在伺服控制系统中的应用

在分析了直流无刷电机伺服控制系统的基础上,提出了一种混合模糊PID跟踪控制器模型.该模糊PID控制器由3个并行的次模糊控制器组成,应用模糊算法在线自动整定PID参数;并利用Matlab/simulink建立仿真模型对模糊推理控制算法进行验证.仿真结果表明,混合模糊PID控制器的动静态特性优于传统单一的PID控制,对设计性能优良的伺服控制系统具有借鉴意义.     

基于多模型模糊自适应PID的无人机纵向姿态控制研究

针对无人机典型的非线性,且气动参数随着工作环境时变的问题,文中研究了基于模糊控制规则下的多模型模糊自适应控制方法,以实现对无人机纵向姿态控制;该方法对局部采用经典PID设计的子控制器进行加权处理,从而达到多控制器集的平滑切换,在利用S函数建立的无人机六自由度模型基础上进行控制仿真,得出仿真曲线;基于无人机纵向姿态俯仰角控制仿真结果表明,设计的多模型模糊自适应PID控制器具有较好的控制性能和鲁棒性。     

直流无刷电机控制器设计与仿真

关于无刷电机性能优化问题。无刷直流电机工作过程中电气参数具有非线性、时变性的特性,造成实时性差,由于传统的PID控制器的参数不能在线调整,在对其进行控制时存在鲁棒性差、精度低等缺点。为解决上述问题,提出将模糊自适应PID控制器应用于无刷直流电机的控制中,根据系统的转速偏差e和偏差变化率ec,经过模糊逻辑推理,动态自适应调整PID控制器的三个参数。在分析电机模型的基础上,借助在Matlab仿真平台设计了无刷直流电机模糊自适应PID控制器的仿真模型。结果表明:较之传统的PID控制器,模糊自适应PID控制器响应速度快、鲁棒性强、无超调、精度高,达到了较好的控制效果。     

小型固定翼无人机纵向姿态控制律的研究

针对无人机在实际飞行过程中受到外部环境影响大,控制精度不够高的问题;研究了一种模糊参数自整定PID控制方法来完成对无人机的纵向姿态的控制;该方法在传统的PID控制的基础上,利用无人机实际飞行中的数据,建立起模糊控制规则来实现PID参数自整定,最后在通过建立的纵向姿态模型上进行仿真控制,得出仿真曲线;仿真实验结果表明,所设计的模糊PID控制器,相比于传统的PID控制器具有更好的控制性能,并且具有很好的抗干扰能力,能够满足无人机控制系统的要求。     

采用遗传优化自适应模糊PID控制球杆系统

为解决球杆系统动态、静态性能不高的问题,提出了遗传算法优化自适应模糊PID控制器的控制方法.该模型在拉格朗日方程建立球杆系统数学模型的基础上,采用遗传算法优化模糊控制规则、隶属函数和自适应PID参数.在GBB1004系统中建立了遗传算法优化后的自适应模糊PID控制器以及控制模型,并对该控制器进行实验验证.实验结果证明了遗传算法优化后的模糊控制器有效地减小了系统的超调量,缩短了系统的调节时间,能够较好地控制球杆系统.     

基于模糊-PID的智能飞控技术研究

由于无人机在飞行过程中机体参数变化剧烈,针对某型无人机,通过对无人机运动学模型进行分析,以无人机纵向运动模型为验证平台,论证了模糊PID技术应用于无人机自动驾驶仪设计的可行性。将传统的PID控制与模糊控制相结合,通过PID控制实现控制的准确性,利用模糊控制提高控制的快速性。针对无人机飞行控制中的实际问题,着重提出了PID控制器和基于误差分区的模糊控制器的设计方法。实验证明该方法不仅增强了控制器的调节能力,还在一定程度上简化了控制器的设计。     

改进遗传算法优化的矿井局部通风机模糊PID控制器设计

目前局部通风机控制主要采用传统PID控制器,控制器的参数固定且多依据经验选取,很难实现隶属度函数和模糊规则的最优组合,使得控制器难以满足局部通风机自适应的控制要求。针对该问题,设计了一种改进遗传算法优化的矿井局部通风机模糊PID控制器。在改进遗传算法中引入欧氏距离提高种群的多样性,同时引入自适应交叉和变异概率来提高算法的收敛性。在编码过程中采用比例分数间接实现对隶属度函数的优化,使得改进遗传算法能够同时优化隶属度函数和模糊规则。将优化得到的隶属度函数和模糊规则导入模糊PID控制器中,控制器能够根据局部通风机的不同工作状态,通过变频器自适应调整局部通风机的风量,实现对局部通风机的动态调节。仿真结果表明,相较于传统模糊PID控制器,改进模糊PID控制器可基本实现无超调,且上升时间缩短了56.25%,稳定时间缩短了47.06%,能够更好地满足矿井局部通风机的控制要求。     

主动磁悬浮系统的变论域自适应模糊PID控制

针对主动磁悬浮轴承系统具有强非线性、强耦合、模型不确定等特点,提出了一种变论域自适应模糊PID算法;该方法通过选择合适的伸缩因子,避免了传统模糊PID控制中出现规则爆炸的问题;同时针对传统伸缩因子的函数结构和参数难以确定的特点,设计了基于模糊规则的论域伸缩因子;在SIMULINK环境中对主动磁悬浮轴承系统进行仿真,仿真结果表明,变论域模糊PID算法控制的主动磁悬浮系统具有更好的动静态性能,对外界干扰具有更强的鲁棒性.     

Only connect: teaching, technology and telesis

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.     

European Community policy and the market

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.     

一种自适应子融合集成多分类器方法

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。     

Avoiding semantic and temporal gaps in developing software intensive systems

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.     

Designing economic np control charts: A programmed simulation approach

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.     

The development of robot art

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     

Explanation and prediction: an architecture for default and abductive reasoning

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.     

Three Process Perspectives: Organizations, Teams, and People

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.     

基于复小波噪声方差显著修正的SAR图像去噪

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。     

How do children do mathematics with LOGO?

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.