带式输送机低速大转矩直驱滚筒控制方案

针对带式输送机主滚筒采用异步电动机配合液力偶合器的驱动方式存在效率低、启动冲击大等问题,提出基于外转子永磁同步电动机(PMSM)的带式输送机直驱滚筒控制方案。为实现低速大转矩控制,采用基于旋转坐标系直轴电流为零的矢量控制策略;针对低速运行时反电动势小、转子位置和速度估算精度低的问题,引入高频脉振信号注入法来估算转子位置及速度。建立直驱滚筒调速控制系统实验平台,进行了稳态特性测试、启动特性测试、负载特性测试,验证了PMSM直驱滚筒控制系统在0～90r/min转速范围内转矩响应快速,转速稳定可调,较好地满足了带式输送机低速大转矩的启动调速要求。     

VFD—C2000系列变频器在地面直驱螺杆泵上的应用

地面直驱螺杆泵采油系统以其结构简单、噪音小、耗能低、投资少、使用方便、维修简便等特点,已成为一种高效的机械式采油设备。本文详细介绍了直驱螺杆泵系统的组成和工作原理以及作为为控制系统核心的台达C2000系列变频器在螺杆泵正转和制动过程中的应用,同时结合机械特性与电气控制原理,合理地解决了由于直驱螺杆泵的反转特性导致的一系列问题,使得系统运行更加稳定和可靠。     

永磁直驱滚筒在带式输送机中的应用研究

带式输送机传统驱动模式为三相异步电动机+减速或调速机构,存在体积大、损耗大、能耗偏高、维修量大等问题。针对该问题,提出将永磁直驱滚筒应用于带式输送机中。分析了永磁直驱滚筒的优势：采用永磁直驱滚筒的带式输送系统更容易实现连续无极调速、低速大转矩运行,更加符合智能矿山的建设要求。介绍了永磁直驱滚筒应用的关键技术,包括永磁直驱滚筒失步控制技术和低速大转矩运行技术。     

基于dSPACE的EV电机系统SPS测试平台设计

为了更好地了解电动汽车电机系统的参数特性,提高电机系统的工作运行效率,基于dSPACE搭建了电动汽车电机系统半实物仿真测试平台。利用dSPACE软件和Matlab/Simulink搭建仿真测试模型,结合实际的动力电池和电机系统,完成平台的建立。通过测试平台在不同转速和转矩情况下,对电动汽车电机系统的驱动特性、制动特性和效率特性进行了实验测试研究,分析了特定工况点下电机系统直流母线电压和电流的响应特性,验证了响应的快速性。通过效率实验确定了高效工作区与电机转速、转矩的关系。因此,设计的测试平台可以很方便地进行电机驱动和制动特性的测试,确定电机的高效工作转速和转矩,对电动汽车驱动和制动行驶工况的选取具有重要意义。     

生产机械的负载转矩特性分析

电力拖动系统的运动方程式中包括了电动机的电磁转矩、生产机械的负载转矩与转速之间的关系,定量的描述了拖动系统的运动规律。但是,要对运动方程式求解,首先必须知道电动机的机械特性和负载特性。负载转矩特性是指生产机械工作机构的转矩与转速之间的函数关系,即。不同的生产机械其负载转矩特性也不相同,本文主要对几种典型的负载转矩特性进行了分析和介绍。     

面向直驱风力发电系统的控制算法优化设计

针对直驱风力发电机组的功率输出不稳定、频率波动超出安全范围问题，该文提出了一种基于深度学习网络预测控制的直驱风力发电系统控制策略。以直驱风力发电系统的频率误差和输出功率为优化目标函数，并将系统的频率变化及风力发电机的转矩限制作为约束条件，利用时间卷积神经网络（TCN）与门控循环单元（GRU）构建预测模型。可行性验证结果表明，在低风速及高风速下有功功率输出的标准差分别为0.04 MW及0.05MW，轴转矩标准差分别为0.01 MNm与0.05 MNm，推力标准差分别为0.04 MN和0.05 MN，证明了该策略可有效降低直驱风力发电系统输出功率的频率波动。     

基于外转子式正弦波无槽无刷力矩电机的超低速高精度伺服系统

阐述了基于外转子稀土永磁正弦波无槽无刷力矩电机直接转矩控制的数字式超低速高精度伺服系统的工作原理、系统构成、控制策略和功能实现.系统实测结果表明,可实现优越的精度和稳定的超低速运行特性.     

虚拟转速转矩功率测试系统

设计基于虚拟仪器技术的转速、转矩、功率自动测试系统。该系统采用图形化编程语言LabVIEW语言设计，能够实现对旋转轴动力参数转速、转矩、功率的测量，并能实现数据的自动采集、保存、处理。由于该虚拟测试系统采用无线网络进行数据传输，其信号采集与信号处理相分离，对于移动机械和作业环境恶劣的测试场所，其应用范围广。     

基于双PWM协调控制的永磁风力发电系统研究

说明了直驱式永磁风力发电系统的基本组成和原理,分析了永磁风力发电系统最大功率跟踪的控制策略;设计了发电系统网侧变流器基于电网电压矢量定向、机侧变流器基于发电机转子磁链定向的背靠背双PWM协调控制结构.最后通过仿真验证了该系统的最大功率跟踪特性,并就仿真中PI参数设置的关键问题进行了说明,可有效防止转速比较控制中的转矩冲击问题.     

直驱式永磁同步风电机组最大功率跟踪控制策略的研究

直驱永磁同步发电机具有直接驱动、结构简单、效率较高等优点,因而成为目前兆瓦级风电机组的主流机型之一,且市场份额有逐步扩大的趋势。以直驱式永磁风力发电系统为主要研究对象,在直驱永磁同步风力发电机(DDPMG)的运行特性基本原理基础上,建立包括风力机、直驱式永磁同步发电机及机侧变换器在内的整个系统的数学模型。应用定子磁链定向的方法,对系统进行矢量控制策略的研究,运用Matlab/Simulink建立了直驱永磁同步发电系统仿真模型,对风速阶跃变化时机组运行情况进行了仿真,结果验证了所建模型的合理性及控制策略的正确性和可行性。     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。