基于Profibus-DP的开放式数控系统高速通信

介绍了在开放式数控系统中使用主站卡与交流伺服驱动从站模块建立Profibus-DP网络.在Visual C 6.0环境下开发用于数据高速通信的接口程序.使用PID算法实现了对多个电机的同时控制,并在"SKY-2007"开放式数控系统中检验了通信的实时性.     

交流伺服驱动在激光标记机中的应用

介绍了激光标记机控制系统，对计算机与系统之间接口模板及交流伺服驱动进行了简要介绍，最后给出了计算机控制运行轨迹的插补运算流程图。     

基于DeviceNet协议的交流伺服驱动器现场总线接口设计

针对交流伺服驱动器智能化与网络化的发展趋势,分析了基于CAN总线的应用层协议DeviceNet的技术特点;采用DSP处理器TMS320F2812和交流伺服控制芯片IRMCK201设计了交流伺服驱动器的控制系统,并提出了利用De-viceNet协议设计伺服驱动器的现场总线接口的方法;完成了DeviceNet现场总线接口的硬件和软件设计。     

西门子推出Sinamics V90伺服驱动系统

2013年8月30日,西门子(中国)有限公司工业业务领域驱动技术集团推出了一款应用于标准运动控制的Sinamics V90伺服驱动系统。该系统包括最新研发并生产的Sinamics V90驱动器和Simotics S-1FL6伺服电机,可以实现位置、速度和扭矩三种控制模式,适用于各种行业和应用需求。此外,该伺服驱动系统可与Simatic PLC(或带有脉冲接口的Simotion运动控制器)、Simatic人机界面和Sinamics V20变频器相结合,组成一套更全面、经     

SICK,发起数字接口的革命

1985年,SICK公司推出专利的同步串行接口SSI,用简单的4条线代替了原来复杂的24条并行数据线,大大简化了接线,降低了故障率,该技术已成为工业环境中无可争议的新标准;1996年,SICK重新发布创新性伺服反馈编码器专用接口——H1PERFACE(@):驱动器安装一个接口即可满足所有应用需求,且驱动器和反馈系统之间只需一条信号电缆——这为行业设立了一项全新的世界标准;2011年,SICK重磅出击,在业内掀起一股数字接口革命的风潮,一款纯数字协议HIPERFACE(@) DSL震撼登场.与混合接口相反,HIPERFACE(@) DSL接口完全实现了数字化,可以帮助彻底提高伺服驱动系统性能,提供全新的功能.     

伺服驱动单元SERCOS总线接口的设计与实现

基于SECOS总线实现控制器与伺服驱动单元的互连已成为数控系统的发展趋势,本文在介绍了SERCON410B芯片结构和功能的基础上,详细探讨了伺服驱动单元SERCOS总线接口的硬件组成和软件实现。     

多媒体计算机的基本配置之二

1.硬盘驱动器硬盘驱动器与软盘驱动器都是计算机的外部磁介质存储设备。硬盘驱动器通过扁平电缆线与硬盘驱动控制设备连通,不同的接口标准有着不同的连接方法。常用的接口有两种:一种是增强型小型设备接口(EnhancedIntegrated Device Electronics缩写为EIDE);一种是小型计算机界面接口(Small Computer SystemInterface缩写为SCSI)。* EIDE(增强型小型设备接口),最多可以连接4个硬盘驱动器,与硬盘连接的是1根40/80线的扁平电缆线。目前硬盘一般采用支持ATA100传输规范、转速为7200 rpm(转/分)、缓存容量为2MB的硬盘。* SCSI(小型…     

开放式控制系统中SERCOS总线的接口设计与实现

目前,市场对适合中小批量加工、具有良好柔性和多功能性的制造系统的需求已逐步超过对大型单一功能的制造系统的需求;这一趋势促成了模块化、可重构、可扩充的开放式控制系统的产生;为了推动国内数控系统的开放性进程,对一种开放式运动控制总线一SERCOS总线进行了研究,并通过设计出嵌入到伺服驱动器中的SERCOS接口卡,实现了完整的主从环形通讯;该接口卡软、硬件的成功设计证明了国内有能力研发出具有SERCOS接口的数控产品,将有利于开放式控制系统在中国的发展。     

基于VC++与PMAC的机器人控制软件的开发

以IPC DSP作为六自由度工业机器人的控制器,设计了一种基于可编程多轴控制器PMAC(Programmable Multi-Axies Controller)的开放式机器人控制系统.采用Visual C 编制控制程序,将机器人系统中管理、控制功能的实现分为若干个模块,负责底层伺服驱动的函数利用PMAC运动语言编写,可直接调用.整个控制软件能完成数据及运动状态显示、伺服驱动、机器人路径规划及定位等任务.实践证明该机器人控制系统运行平稳.     

基于ARM+Linux的直流伺服控制系统设计

目前大多伺服控制系统依赖计算机实现,系统体积功耗大、成本高。针对此问题,以ARM9 S3C2440芯片和CPLD EPM570T144芯片为硬件平台,在嵌入式Linux操作系统下设计了直流伺服控制系统。ARM实现控制算法,得出控制量给CPLD,CPLD主要用作控制接口扩展和信号处理。详细介绍了Linux设备驱动设计和伺服控制应用程序设计。实验结果证明,系统能够实现等速跟踪、位置跟踪和正弦跟踪等控制功能,并能实现复杂控制算法,以满足控制系统实时性和高速性要求。     

Transitioning from the ecological fieldwork to an online repository: a digital library solution and evaluation

This article presents a digital library solution for integrating data from a network of ecological sites using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) and the Open Digital Library (ODL) framework extended with geographic components. This solution incorporates simple, yet effective, decentralized input interfaces for handling heterogeneous data from unstructured sources. In this article, we focus on the architectural aspects of this solution and on an experimental evaluation, conducted with real users, of the proposed data input interface in terms of usability and data quality.     

Adding value to Linked Open Data using a multidimensional model approach based on the RDF Data Cube vocabulary

Most organisations using Open Data currently focus on data processing and analysis. However, although Open Data may be available online, these data are generally of poor quality, thus discouraging others from contributing to and reusing them. This paper describes an approach to publish statistical data from public repositories by using Semantic Web standards published by the W3C, such as RDF and SPARQL, in order to facilitate the analysis of multidimensional models. We have defined a framework based on the entire lifecycle of data publication including a novel step of Linked Open Data assessment and the use of external repositories as knowledge base for data enrichment. As a result, users are able to interact with the data generated according to the RDF Data Cube vocabulary, which makes it possible for general users to avoid the complexity of SPARQL when analysing data. The use case was applied to the Barcelona Open Data platform and revealed the benefits of the application of our approach, such as helping in the decision-making process.     

Piazza问答平台与Open edX平台的集成

Piazza问答平台与Open edX学习平台两者相互独立,影响用户使用,并且Piazza问答数据无法被高效利用。针对上述问题 ,对Piazza问答数据进行持久保存, 利用多标签过滤方法提高了Piazza问答数据的查找能力;基于Piazza-Xblock插件,实现了在Open edX平台查找和展现Piazza问答数据,以及通过URL参数直接访问Piazza特定页面的功能,达到Piazza问答平台与Open edX平台有机结合的效果。     

Open Divx视频编码程序的并行性分析与优化研究

Open Divx是一种基于MPEG-4思想开发的视频压缩软件。为了解决嵌入式条件下视频数据的实时压缩问题，本文对Open Divx视频编码程序进行了循环级并行性和指令级并行性的分析。最后，我们得出了Open Divx视频编码程序更适合于在采用多整数运算功能部件的体系结构环境下运行的结论。     

Standards-Based Computing Capabilities for Distributed Geospatial Applications

Researchers face increasingly large repositories of geospatial data stored in different locations and in various formats. To address this problem, the Open Geospatial Consortium and the Open Grid Forum are collaborating to develop standards for distributed geospatial computing.     

基于RTLinux的开放式软件PLC的研究*

开放式控制技术是工业控制技术的发展趋势之一,软件PLC是开放式控制系统的重要组成部分。开放式控制系统实现的一条重要途径就是充分利用PC的软硬件资源,最大限度地利用软件实现控制功能。通过软件分层与数据开放相结合的方法,在RTLinux下设计的开放式软件PLC就是这种思想体现。     

Viscous Open Data: The Roles of Intermediaries in an Open Data Ecosystem

Open data have the potential to improve the governance of universities as public institutions. In addition, open data are likely to increase the quality, efficacy and efficiency of the research and analysis of higher education systems by providing a shared empirical base for critical interrogation and reinterpretation. Drawing on research conducted by the Emerging Impacts of Open Data in Developing Countries project, and using an ecosystems approach, this research paper considers the supply, demand and use of open data as well as the roles of intermediaries in the governance of South African public higher education. It shows that government's higher education database is a closed and isolated data source in the data ecosystem; and that the open data that are made available by government is inaccessible and rarely used. In contrast, government data made available by data intermediaries in the ecosystem are being used by key stakeholders. Intermediaries are found to play several important roles in the ecosystem: (i) they increase the accessibility and utility of data; (ii) they may assume the role of a “keystone species” in a data ecosystem; and (iii) they have the potential to democratize the impacts and use of open data. The article concludes that despite poor data provision by government, the public university governance open data ecosystem has evolved because intermediaries in the ecosystem have reduced the viscosity of government data. Further increasing the fluidity of government open data will improve access and ensure the sustainability of open data supply in the ecosystem.     

Open Set face recognition using transduction

This paper motivates and describes a novel realization of transductive inference that can address the open set face recognition task. Open set operates under the assumption that not all the test probes have mates in the gallery. It either detects the presence of some biometric signature within the gallery and finds its identity or rejects it, i.e., it provides for the "none of the above" answer. The main contribution of the paper is open set TCM-kNN (transduction confidence machine-k nearest neighbors), which is suitable for multiclass authentication operational scenarios that have to include a rejection option for classes never enrolled in the gallery. Open set TCM-kNN, driven by the relation between transduction and Kolmogorov complexity, provides a local estimation of the likelihood ratio needed for detection tasks. We provide extensive experimental data to show the feasibility, robustness, and comparative advantages of open set TCM-kNN on open set identification and watch list (surveillance) tasks using challenging FERET data. Last, we analyze the error structure driven by the fact that most of the errors in identification are due to a relatively small number of face patterns. Open set TCM-kNN is shown to be suitable for PSEI (pattern specific error inhomogeneities) error analysis in order to identify difficult to recognize faces. PSEI analysis improves biometric performance by removing a small number of those difficult to recognize faces responsible for much of the original error in performance and/or by using data fusion.     

对开放系统互联OSI有关重要概念的分析

论文从系统的高度对计算机网络体系的国际标准──开放系统互联ＯＳＩ所涉及的一些重要概念进行了分析。最后，论文还对ＯＳＩ与网络开放应用体系结构ＯＡＡ的关系进行了分析。     

基于开源Hadoop的矢量空间数据分布式处理研究

为实现大规模矢量数据的高性能处理,在开源项目Hadoop基础上,设计与开发了一个基于MapReduce的矢量数据分布式计算系统。根据矢量空间数据的特点,通过分析Key/Value数据模型及GeoJSON地理数据编码格式,构建了可存储于Hadoop hdfs的矢量数据Key/Value文本文件格式;探讨矢量数据的MapReduce计算过程,对Map数据分片、并行处理过程及Reduce结果合并等关键步骤进行了详细阐述;基于上述技术,建立了矢量数据分布式计算原型系统,详细介绍系统组成,并将其应用于处理关中地区1∶10万土地利用矢量空间数据,取得较好效果。