基于高阶控制器设计的线性自抗扰控制参数调整

将反馈控制器/扩张状态观测器闭环极点配置在同一位置是线性自抗扰控制器(linear active disturbance rejection control,LADRC)最常用的整定方法.该方法只需调整两个参数,在工程应用上极为方便.但是,由于极点配置在同一位置的限制,整定的LADRC可能达不到期望的性能.本文提出以现有控制器参数为基础的LADRC调参方法.该方法以现有控制器参数为基础,通过降阶及逼近,保证LADRC控制能接近现有控制系统的性能.仿真设计表明采用高阶控制器设计的LADRC可以取得与原有控制系统相当的控制性能.该方法不受带宽法调参的需使反馈控制器及扩张观测器极点配置在同一位置的限制,因此可以期望获得比带宽法更好的性能.同时,该方法为已经熟悉掌握其他控制器设计方法的工程控制人员提供了一种便捷的调整线性自抗扰控制参数的方案,具有较好的应用价值.     

PMSM伺服系统线性自抗扰控制器的参数整定

当自抗扰控制器在工程中应用时,控制器性能和参数整定难易决定了其可推广性.本文阐述了一种将PI控制器改造为线性自抗扰控制器(LADRC)的方法,并给出了参数整定规则.首先,本文对于永磁同步(PMSM)伺服系统"位置–速度–电流"三闭环控制建立了"P+P/I+P/I"结构的控制模型,并通过极点配置的方法将控制器参数整定转换...     

基于神经网络的非线性扩张状态观测器

自抗扰控制方法是一种新型的非线性设计方法,在自抗扰控制器中主要存在着确定待定参数的问题;非线性扩张状态观测器是自抗扰控制器的核心,在研究非线性扩张观测器中的参数整定问题时,将神经网络的思想引入参数整定,提出了基于神经网络的非线性扩张状态观测器的设计方法,运用该方法可以对任意阶的非线性扩张状态观测器进行参数设计;大量仿真算例表明,设计出的观测器具有良好的鲁棒性,有一定工程应用参考价值.     

内模控制框架下时延系统扩张状态观测器参数整定

作为一种有效的控制设计方法, 自抗扰控制研究获得了广泛关注, 然而针对自抗扰控制器的参数整定方法则相对较少. 本文针对一阶惯性加延迟系统, 将线性自抗扰控制转化为内模控制结构, 导出了其中控制器、滤波器、乘性不确定性、互补灵敏度函数的对应表达式, 随后, 利用频域鲁棒稳定性判据, 分析了自抗扰控制器核心—–扩张状态观测器的参数对闭环系统稳定性的影响. 基于该分析, 总结出一阶惯性加延迟系统扩张状态观测器的两条参数整定准则. 数值仿真结果验证了该整定准则的有效性.     

线性自抗扰控制参数b0 辨识及参数整定规律

针对自抗扰控制中参数b0 整定困难的问题, 提出一种新的参数辨识方法, 对线性自抗扰控制器(LADRC) 中的参数b0 进行辨识, 并提出了LADRC参数整定的基本规律. 通过频域分析研究了控制器参数b₀ 和控制器带宽b₀ 的变化对闭环系统扰动抑制能力的影响. 通过分析闭环控制系统的稳定区域研究了控制器的鲁棒性. 仿真结果表明, 根据辨识得到的b0 可以快速整定LADRC的参数, 使LADRC具有较强的鲁棒性.

     

一阶时滞系统线性自抗扰控制器参数稳定域分析

当使用线性自抗扰控制器(linear active disturbance rejection controller,LADRC)控制时滞系统时,闭环系统的稳定性与控制器参数的选取有较大的关系.如何定量求取线性自抗扰针对时滞系统的参数稳定域还没有有效的方法.本文针对线性自抗扰控制器控制一阶时滞系统,利用双轨迹法精确求解出了线性自抗扰控制器参数的稳定域.该方法利用双轨迹的图形性质,有效地将求解具有时滞的控制系统闭环特征方程根的分布问题转化为求解双轨迹交点频率的问题,从而得到能够保证闭环系统稳定性的控制器参数稳定域.求得的稳定域为时滞系统线性自抗扰控制器的整定提供了理论依据.仿真结果验证了所提出方法的有效性.     

立方体机器人自抗扰平衡控制方法

针对立方体机器人动力学模型多变量、强耦合的问题,提出一种基于自抗扰控制的平衡控制器设计方法.引入虚拟控制量,并在控制量与输出向量之间并行地嵌入多个自抗扰控制器,从而实现对多变量系统的解耦控制,将系统的动态耦合和外部扰动视为各自通道上的自抗扰控制器的总扰动,在为期望姿态安排过渡过程基础上,设计扩张状态观测器对总扰动进行估计并实时补偿.综合采用经验试凑法和带宽法对控制器参数进行整定,对自抗扰控制器系统进行稳定控制、姿态跟踪、抗扰性和鲁棒性实验,并与PID控制系统进行定量对比分析.仿真结果表明,所设计的自抗扰控制器不仅能有效实现立方体机器人的平衡控制,而且较PID控制器具有更好的响应速度、控制精度和强鲁棒性.     

线性自抗扰控制的适用性及整定

线性自抗扰控制将被控对象看成串级积分系统,把其他信息都当成不确定性.这种处理方法简单,但是对什么样的系统有效,目前还没有理论给出确定的答案.本文证明任何带有积分行为的严格正则传递函数都可以由线性自抗扰控制的反馈控制器等价实现,从而表明线性自抗扰控制具有广泛的适用性,即只要其他线性控制方法能够控制的系统,线性自抗扰控制同样可以适用.为简化线性自抗扰控制器参数整定,本文针对工业过程中广泛存在的PID控制器,提出将PID参数转化为二阶自抗扰控制参数的方法.该方法转化的线性自抗扰参数以带宽形式表示,从而保留了传统线性自抗扰简单易调的特性,为线性自抗扰控制在工业过程的应用准备了基础.     

带扰动观测器的模糊自整定调节系统研究

针对双容液面调节系统的非线性、参数时变的特点,基于现代控制理论设计了带扰动观测器的模糊自整定控制器。该方案既实现了PID控制器参数的在线自整定,又增强了系统的抗扰能力。仿真试验表明,该方案极大地提高了被控对象的静态和动态性能,对参数时变的适应能力强、鲁棒性好。     

高阶线性自抗扰控制器的性能评估

以二阶系统为研究对象,在线性扩张观测器(LESO)的基础上,给出高增益形式的高阶LESO.基于高阶线性自抗扰控制器(HLADRC)二自由度闭环传递函数和频域特性曲线,证明了其状态估计误差的收敛性以及高阶线性自抗扰控制器的稳定性.同时,系统地分析了输入增益和模型参数不确定性对稳定鲁棒性的影响,推导出满足系统稳定条件的参数??的稳定域以及系统干扰抑制动态特性与带宽的关系.最后,通过与线性自抗扰控制器(LADRC)的对比仿真表明, HLADRC在干扰抑制方面具有很大的优势,而LADRC在稳定鲁棒性和控制品质方面具有更好的效果,从而为工程设计提供了理论依据和实践参考.     

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     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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。