基于FlexRay总线的多节点通信设计

针对FleaRay总线在分布式测控系统中多节点传输控制过程中功能单一的问题，将微控制器、通信控制器、总线收发器等组成电子控制单元，实现多节点网络间的静态段和动态段的数据收发通信等功能。实验表明：组成的通信网络的节点之间可进行数据收发，传输过程中无丢帧、错帧，满足分布式测控系统的可靠、精准要求。     

基于网络通信的分布式微小位移测量系统

介绍一种分布式微小位移精确测量系统,该系统基于网络通信技术,采用FPGA和线阵CCD实现.在系统中,通过FPGA逻辑设计实现线阵CCD的高速驱动,使线阵CCD的数据传输率达到每秒5 000帧,网络通信技术实现了数据的远距离传输和支持多站能力,基于VB平台编写PC机控制程序.系统已应用在一维微小形变的测试中,可以支持32个线阵CCD测试节点,节点数据传输长度大于1000m,测量精度达到100μm.     

电力系统负荷处理在嵌入式平台上的实现与研究

通过设计新型嵌入式处理终端,将传统的电力负荷管理终端和新的分布式电源监控相结合,把分布式电源纳入配电网自动化系统的负荷管理,并实现电源和负荷的本地监控．设计并完成嵌入式处理终端和本地监控中心的软硬件开发接入点测控单元以ARM9为核心,实现对接入点的遥测、遥信、遥控、网络通信等功能嵌入式管理终端以Wince操作系统为核心,包括下层通信、上层通信、负荷管理、远方抄表、电能量分析、发电管理、分布式电源接入点管理等功能模块本地监控中心软件分为前置处理、实时数据服务、历史数据库以及人机交互界面．通过搭建实验测试平台证明该系统满足可靠、规范的通信、控制管理,与现有系统兼容等需求．本文在系统的软件、硬件方面做了详细的阐述。     

机载分布式高速测试总线设计与验证

中短距离分布式高速总线是航空机载测试设备发展的关键技术之一,能够高效解决复杂机载测试环境中分布式采集系统的总线传输问题。基于MLVDS标准收发器,设计一种传输距离10～100 m的中短距离分布式高速总线,建立物理层拓扑架构模型,并对其基带信号传输特性进行理论计算分析,确定分支线长度、连接器和最小接点距离3个关键参数,最后搭建分布式高速总线的传输物理模型,并进行理论最严苛配置的机载高低温环境下的基本性能测试。测试结果表明:该分布式高速总线参数设计合理,通信性能优良,通信质量可靠,可为多类型专用机载分布式参数采集系统的开发提供总线传输基础。     

Profinet CBA在厦烟“金桥”制丝生产线中的应用研究

RROFINET CBA是一种基于组件的自动化技术,通过采用标准自动化组件实现分布式自动化系统之间的通讯,介绍厦烟"金桥"制丝生产线基于Profinet技术的集控系统总体架构,研究如何应用PROFINETCBA技术实现分布式自动化系统之间的实时通信,这对构建基于PROFINETCBA的分布式实时通信系统具有较强的借鉴意义。     

TCP／IP技术在监测系统中的应用

针对工业电磁环境监测系统中测点位置变化性强的特点,考虑到LabVIEW中动态创建控件的不足,提出了一种基于网络TCP/IP技术的数据传输方法,实现了LabVIEW和Delphi两种开发平台之间的数据实时传输与共享,为现场工业电磁环境监测的实现提供了保证.该方法实现简单、运行可靠,灵活性强.     

远程分布式多LED显示屏控制系统研究

综合单片机、网络通信技术、远程视频技术,提出了一种基于RS-485总线的主从分布式远程LED显示屏控制系统,可实现对多显示屏的远程监控及显示内容的动态刷新,并可将显示内容在PC机上进行预览.介绍了该系统的总体设计方案、软硬件构成,并详细阐述了多LED显示屏的远程通信原理及实现方法.     

浅论思科网真系统的兼容性

在网络通信系统的支持下,视频会议系统实现实时可交互的视频、语音、文字、白板等传输。随着视频通讯技术的发展及应用,工作效率和工作质量求在不断提高,高质量视频会议系统将成为现代化办公建设的重组成部分,网真系统是一种全新的高质量视频系统技术,它结合智能化P网络、统一通信、超高清IP视频、空间IP音频、交互式协同组件、数字电影、灯光环境、人体工程等领域一系列的集成技术,成功进行了系统性创新,实现跨越空间和技术障碍的真实体验。而现有网真系统技术主流厂商遵循的视音频通信协议、实现的工艺各不相同,不能很好的结合传统视频系统平滑扩容升级,同时满足将来能够向更高带宽和更高图象质量扩展。本文基于思科网真系统,讲述网真系统技术的兼容性问题。     

网络捕获编程的基础

随着对网络工作的深入，需要对网络数据包进行捕获，就要用到套接字的知识。套接字是支持TCP／IP的网络通信的基本操作单元，可以看作是不同主机之间的进程进行双向通信的端面点，简单的说就是通信的两方的一种约定，用套接字中的相关函数来完成通信过程。     

测控数据在IP网传输的实时性分析

传统的DDN-TDM技术实时传输测控数据的方式,将逐渐被IP以太网技术所取代。从实时测控数据的特性及其对通信传输的要求出发,对IP网的传输时延进行较为全面的分析,对影响实时传输的因素进行论述,同时对TCP和UDP协议进行比对,并提出解决实时通信的方法。     

Fast approximate methods for the reliability analysis of computer networks

The complexity of computer communication networks has taken a dramatic upswing, following significant developments in electronic technology such as medium and large scale integrated circuits and microprocessors. Although components of a computer communication network are broadly classified into software, hardware and communications, the most important problem is that of ensuring the reliable flow of information from source to destination. An important parameter in the analysis of these networks is to find the probability of obtaining a situation in which each node in the network communicates with all other remaining communication centres (nodes). This probability, termed as overall reliability, can be determined using the concept of spanning trees. As the exact reliability evaluation becomes unmanageable even for a reasonable sized system, we present an approximate technique using clustering methods. It has been shown that when component reliability ⩾ 0.9, the suggested technique gives results quite close to those obtained by exact methods with an enormous saving in computation time and memory usage. For still quicker reliability analysis while designing the topological configuration of real-time computer systems, an empirical form of the reliability index is proposed which serves as a fairly good indicator of overall reliability and can be easily incorporated in a design procedure, such as local search, to design maximally reliable computer communication network.     

CONCORD: A Control Framework for Distributed Real-Time Systems

Novel network technology combined with advances in hardware development have permitted the enabling of distributed real-time systems and have shortened the time-to-market period. Distributed frameworks, also known as middleware, are often used to integrate enterprise systems, shorten the development time, and reduce complexity. However, to deploy standard middleware in robotics and control applications, we have to deal with the challenge of producing predictable outputs. Most real-time applications in these areas are developed in ad hoc manner, and as such, it is hard to migrate them to new platforms. To overcome this issue while minimizing development effort and increasing reusability for distributed real-time systems, we propose a control framework for distributed real-time systems based on standard middleware specifications. The control framework is composed of asynchronously running task modules, which can be located on either the local or the remote machines. The task modules are connected by an event channel, which uses the publish/subscribe communication method. We also have developed an adaptive event channel in order to meet real-time system requirements and to produce predictable outputs. Detailed development of the control framework along with the adaptive event channel are assessed through a set of experimental results.     

IoT-based networking for humanoid robots

Abstract

In this paper, a new network communication approach, named real-time network (RTNET), is designed and implemented for humanoid robots. The proposed five network objects – alarm, condition, message, mail, and file are used to represent the task and priority of the communication data. Compared to the existing protocols, the network scheduling mechanism of RTNET arranges, more efficiently, the priority and flow control of the five network communication objects to meet real-time requirements for the limited bandwidth of the local area network. RTNET can be further integrated with other protocols, such as EtherCAT or controller area networks (CAN Bus) for local control systems, e.g. robot arms, to improve the communication mechanism. The RTNET can also be used over Ethernet to connect each subsystem and to exchange information among those systems. Also, an Internet of things (IoT) network structure based on RTNET is proposed in this paper. The information of each subsystems is collected through RTNET and users can access all components in the IoT network. In this paper, the concept of RTNET is presented and RTNET has been implemented on a National Taiwan University (NTU) humanoid robot control system with CAN Bus.     

分布式PLC系统在果葡糖浆生产中的应用

文章主要介绍了果葡糖浆的生产工艺过程,阐述了分布式PLC系统的组成及监控过程的实现。实践表明,基于EtherNet/IP的分布式PLC系统具有组态简单、通讯能力强和性能稳定等诸多优点,为生产过程控制提供了可靠的保障。     

经编机电子贾卡混合异构串行通信系统设计

针对传统经编机多板卡架构的电子贾卡控制系统存在的可靠性低、维护困难等问题,设计了一种面向工程应用、高度集成的新型嵌入式电子贾卡导纱针块(embedded electronic jacquard guide bar,EEJGB)。基于EEJGB,提出了一种兼顾通信可靠性和容错性的分布式混合异构串行通信架构,并对该通信架构进行了实时性分析。同时,为获取EEJGB的地址,提出了一种动态分配机制。为了验证该通信方法的有效性和可行性,以Modbus协议下的具体通信方法实例进行试验分析。分析结果表明:所提出的混合异构串行通信架构实时性高,在保证花型文件可靠传输的同时,极大地便利了EEJGB的故障定位、快速检修和分布式扩展,研究结果能够为新一代集成电子贾卡控制系统的设计提供有效的参考。     

电动汽车控制网络实时性分析研究

分析了影响电动汽车分布式控制系统实时性的主要因素,通过对整个网络系统的测试,考察了实际运行的网络的性能是否能够满足汽车动力系统的实时性要求.对目前电动汽车网络中常采用的125kb/s,250kb/s和500kb/s三种通信速率的CAN网络实时性进行了对比测试分析,结果表明:在相同的网络中,总线正常通信的情况下,提高总线通信速率,能有效降低总线负载率;10ms的信息在网络上实时性要求比较高,将主要影响网络实时性能.所得研究结果对制定电动汽车CAN网络协议具有重要参考价值.     

Enhancing smart shop floor management with ubiquitous augmented reality

This paper describes a framework for implementing Smart manufacturing Shop floor systems based on the Ubiquitous Augmented Reality technology (SSUAR). The proposed system makes use of data sharing between shop floor resources and a sensor network in order to optimise the production schedules for carrying out projects. The optimisation is performed in real-time and the production scheduling responds to new projects as well as the changing status of resources, such as machines and workers. Ubiquitous augmented reality interface has been developed and utilised as a user interface for the shop floor workers to receive information, instructions and guidance from the experts and manufacturing systems, and to update the systems on task parameters, such as estimated completion times, progress and machine status. A review of related work, methodology and implementation of the proposed system, and a case study are presented in this paper. Using this architecture, real-time scheduling of tasks in the smart shop floor can be achieved. The case study demonstrated the ability of SSUAR to integrate task scheduling with two-way communication between the system and the users.     

网络环境下实时图像信息处理传输系统

基于 MPEG-IV 编解码技术和 RTP/RTCP 网络传输协议,设计出一种以高速 DSPTMS320C6205 为核心处理器的实时图像信息处理传输系统(IPTS)。系统的总体构架采用Client/Server 模式,由现场视频信息采集前端、信息中心和视频信息传输网络构成。该系统融合了先进图像处理技术、信息技术、数据通信传输技术及自动控制技术等,能实时地采集和处理图像信息,并进行网络传输和控制,是一种范围大、方位全、实时、准确和高效信息综合处理系统。     

Development of a real-time monitoring system as a decision-support system for flood hazard mitigation

This study proposes a real-time monitoring system to integrate the supportive flood-related information for hazard mitigation purposes. Through integrating photography, communication, geometric information display and network technology, this system can provide the real-time monitoring images at the critical gauge stations, inundation-prone areas and important hydraulic facilities during floods. With the development of mobile monitoring modules, the maneuverability of users and facilities could be significantly improved. Users can easily employ mobile phones to receive or report real-time flood-related information at any place and time. Furthermore, the water-level image recognition method is developed and applied to the selected monitoring stations for acquiring early warning of flood events. In final, an application scenario is given to illustrate how this system can greatly improve the effectiveness and efficiency of emergency responses to flood hazard mitigation for the decision-makers.     

Dependable communication synthesis for distributed embedded systems

Embedded control applications such as drive-by-wire in cars require dependable interaction between various sensors, processors, and actuators. This paper addresses the design of low-cost communication networks guaranteeing to meet both the performance and fault-tolerance requirements of such distributed applications. We develop a fault-tolerant allocation and scheduling method, which maps messages onto a low-cost multiple-bus system to ensure predictable inter-processor communication. The proposed method targets time-division multiple access (TDMA) communication protocols, and is applicable to protocols such as FlexRay and TTP which have recently emerged as possible networking standards for embedded systems such as automobile controllers. Finally, we present a case study involving some advanced automotive control applications to show that our approach uses the available network bandwidth efficiently to guarantee message deadlines.