基于DSP和FPGA的多通道RS422总线采集技术研究

在航空测试领域RS422总线被广泛用于数据传输。文章介绍了一种RS422总线信号的多通道采集技术,系统以FPGA和DSP为处理器实时采集总线上的数据信息,根据需求可以进行部分数据或者100%数据的采集,按照传输协议将数据传输给主控并生成网络数据包发送出去。     

基于RS485总线的PC机与FPGA通信系统设计探索

在计算机网络设计初期,通过数据链路协议传递数据是较为普遍的方法,而通过物理链路来实现数据传输稳定性较差,由此,能够保证数据传输可靠性的高级数据链路控制协议(HDLC)被研究出来,这一协议帮助PC机与现场可编程门阵列(FPGA)通信,系统能够通过RS485总线传输控制命令,使得FPGA通信系统的运行受到PC机的控制。本文通过介绍RS465总线对FPGA通信系统的协议控制功能对PC机与FPCA通信系统的设计做出一些深入探究。     

基于VB、Excel和Access的蠕变实验机测控软件系统

数据采集和控制软件系统采用串口通协议,实现了对4台蠕变实验机多点数据采集和数据的自动记录。遵循温度控制器的RS485通讯协议,软件系统可以自动调控蠕变高温炉的温度。通过OLE技术和人工代码,VB与Access、Excel无缝连接,将试验数据保存到Access数据库中。运行结果表明系统的软、硬件工作稳定,可靠性高,完全实现了蠕变实验机的温度自动控制和试验数据的自动记录。     

基于485总线的自动化验的实现

采用RS485总线为自动化验室组建了局域网，将化验器材以及办公所用电脑连接在一起。通过化验器材将化验数据传输给服务器，服务器通过串口监听扑捉实验数据，并与数据库中的标准进行比较，进而评定化验数据是否合格。从而改善了化验室的工作状态，提高了化验室的工作效率以及化验数据的准确性。     

海底管道检测机器人智能控制器的研制

设计了以嵌入式PC104工控机为核心的海底管道检测机器人智能控制器,以嵌入式Linux操作系统作为该智能控制器的软件运行平台,根据控制任务的实时性和计算量的不同,开发的控制程序分别运行于系统实时内核和原Linux内核,满足了控制系统具有实时性、多任务并行处理等要求。详细介绍了管道检测机器人CAN通信应用层协议的定制规则,通过把报文的内容类别信息和节点信息纳入数据帧标识符来规定报文优先级,保证在多个数据帧同时竞争总线时,优先传送紧急程度高的报文。采用RS232-CAN协议转换器构建了具有检验智能控制器功能的试验平台,方便了控制程序的设计与验证。在实验室模拟油气管道台架上和工程现场的应用结果表明,该智能控制器实现了各种工况下的控制决策等功能,达到了设计要求,所设计的通信协议满足系统通讯要求。     

基于北斗通信的河道水质监测系统设计

针对当前水污染监测费时费力的问题,为了实现实时在线检测水质信息,提出了一种基于北斗通信的浮标监测系统,该系统包括浮标体数据采集系统和岸基接收站系统。以新型设计的浮标为载体的数据采集系统,采用STM32芯片,通过RS485协议读取传感器数据后发送并保存至SD卡中;同时通过北斗模块将数据发送至岸基,岸基上位机可远程浏览浮标状态数据、水质数据以及位置信息。整个系统采用太阳能供电方式,以此完成从数据采集、数据保存到数据传输、数据处理。经测试,整个系统运行状况良好,可实现水质自动化监测,达到预期设计要求。     

基于Modbus的主从通信模式的通用化设计

本文根据分层设计思想,基于RS485总线和Modbus协议,实现主从通信模式下的通用化设计,同时满足不同设备和硬件平台下的可移植性和扩展性的需要。另外,设计中利用侦测帧技术,解决子节点信息及时上告的问题。     

基于LabWindows/CVI的取力发电系统测试平台设计

针对目前国内取力发电系统没有专用测试平台和测试方法的现状,为准确测试取力发电系统在各种运行状态下的技术参数,根据不同型号取力发电系统的测试要求,开发了基于虚拟仪器的取力发电系统测试平台。设计中采用了基于LabWindows/CVI环境下的多线程技术,利用RS232协议通过PLC来控制负载的组合和通断,满足对不同功率、电压等级下负载的测试要求。实际测试表明,该套设备性能优异,稳定性高,能较好地满足取力发电系统电能质量的测试要求。     

高可靠性煤矿井下火源无线预警监测系统

鉴于无线ZigBee协议传输数据率低、距离短,为进行煤矿井下大范围高密度火源监测任务,设计一种高可靠性煤矿井下火源无线预警监测系统。在井下煤自燃隐蔽区域布置感温电缆,利用WaveMesh移动自组网协议多跳网络并行传递数据,根据节点路径选择算法选择传输的最佳路径,通过光纤冗余环网传输至监测终端。该系统以可靠性、健壮性和易移植性为设计原则,针对硬件抗干扰和防爆,射频转发相邻节点数据并设置避让机制,WIFI模块或RS485模块及接口模块二选一通信,光纤冗余环网传输数据。经试验表明,无线传感网络最大通信距离为37 m。采用WaveMesh多径路由协议,组成多跳网络在不同路由间自由切换,能够充分利用无线信号的冗余性。     

串行通信测试系统研究与设计

在工业现场中,底层设备常使用RS232、RS422和RS485等接口进行通信,而上位计算机常使用USB接口进行通信。为方便计算机与底层设备之间的通信,设计出一种用于串行通信的系统,能够将USB接口数据和串口数据进行转换,并介绍系统的总体架构、软硬件设计方案,通过VHDL语言设计实现基于FPGA的总线控制器功能。最后,通过Lab VIEW测试程序验证串行通信测试系统的功能。     

Sequencing the storages and retrievals for flow-rack automated storage and retrieval systems with duration-of-stay storage policy

Sequencing of storages and retrievals is an important topic in the automated storage and retrieval system (AS/RS), which largely influences the throughput performance and the operational cost of an AS/RS. In this paper, the problem of sequencing the storages and retrievals in a flow-rack AS/RS with duration-of-stay storage policy is analysed and a two-step heuristic called the grouping-matching method is proposed for minimising the total travel time of operations. The proposed grouping-matching method assigns unit-loads into groups in the grouping step and matches groups and bins of flow rack in the matching step. Two grouping heuristics are designed for the grouping step. The matching subproblem is formulated as an assignment to be solved. Simulation experiments are conducted to evaluate the effectiveness and efficiency of the grouping-matching method and the two grouping heuristics used for the grouping subproblem.     

Electrodeposition based synthesis of S-rich CuIn(S,Se)2 layers for photovoltaic applications: Raman scattering analysis of electrodeposited CuInSe2 precursors

Single step electrodeposition (ED) of Se-rich CuInSe₂ precursors, followed by RTP annealing under sulphurising conditions leading to S-rich CuIn(S,Se)₂ films, constitutes a promising technology for low cost high efficiency solar cells. In this work, a Raman scattering (RS) analysis of Se rich precursors grown under ED conditions leading to different chemical compositions is reported. RS has allowed identification of the main secondary phases in these layers with elemental Se, Cu-Se binary and ordered vacancy compound (OVC) phases. The experimental data show a strong dependence of the spectral contributions related to Se and Cu-Se with the layer molecularity, and the formation of these phases is mainly determined by the content of excess Se in the layers. The correlation of these data with the characteristics of the solar cells fabricated with these precursors, shows the strong impact of the presence of the Cu-Se phase on the performance of the final devices. These results point out the key role played by this binary phase on the formation of secondary phases after the sulphurising step.     

产品包装设计方法管理系统的设计

目的针对目前产品包装设计方法管理不足、重复设计现象严重等现象,设计一个产品包装设计方法管理系统。方法根据产品自身特性及在流通过程中所受外界环境的影响,采用编码技术对产品的包装特性进行总结和等级划分,并将产品包装特性分为高相关特性和低相关特性,以此为依据实现包装设计方法的分类和管理。结果系统主要由方法上传模块、方法检索模块、用户管理模块、方法管理模块和奖励系统组成,在上传包装设计方法时需同时录入对应产品的包装特性。方法检索模块主要采用编码技术、规则推理技术和相似度计算来实现对产品包装设计方法的智能检索。结论该系统上传方便,可按不同要求检索产品包装设计方法,优化了包装设计流程,减少了重复劳动。     

力标准机独立加码与逆程交换研究

静重式力标准机在施加递增或递减负荷过程中，当砝码进行逆程交换时会出现逆负荷现象。为此，提出了力标准机独立加码的概念与方法，建立并讨论了独立加码方法的驱动方式、砝码加卸过程的运动规律、加卸过程中吊挂受力变化、加载稳定性和工作效率问题。研究了通过少量砝码的合理组合与交换，实现多力级等力值间隔加载的技术方法。当砝码进行逆程交换时，为减小以至消除逆负荷现象进行了理论分析和实验验证。结果表明，提出的方法是可行的和有效的。为力基、标准机的技术发展和提高提供了一种新的理论方法和试验依据，对力值计量检测技术的进步具有重要意义。     

光学计量用高速线阵CCD数据采集系统设计

介绍一种采用高速线阵 CCD 数据采集系统的设计过程。通过一片 MicroChip 公司的在线可编程微控制器对采集系统进行控制,并用标准 RS232 串行接口与外部进行数据通信和控制。在时序逻辑设计中,较好地解决了数据的存储、读取和点像元数据连续监测。实际应用表明该系统能满足光学干涉计量中线阵 CCD 数据采集要求。由于可以对线阵 CCD 进行单点、多点和整块数据的读取处理,因而可适应于不同周期、不同像素数目的线阵 CCD 传感器,以满足多种不同需求。     

基于RS算法的汉信码在金融票据系统中的应用研究

针对支票等金融票据在传递过程中的安全和智能化问题,介绍了一种基于Reed-Solomen(RS)算法的汉信码在金融票据中的应用系统。利用DSP高性能的专用数字信号处理芯片TMS320C5402,实现系统的数字控制,快速有效地完成数据编码;在分析RS纠错算法的基础上,利用Simulink仿真平台建立了RS编解码仿真模型图,并给出了相应的仿真结果,为分析与研究汉信码在金融票据系统中的应用提供理论依据。     

Investigation of Residual Stress in 2D Plane Weave Aramid Fibre Composite Plates Using Moiré Interferometry and Hole‐Drilling Technique

Residual stress (RS) is crucial to the fabrications of woven composite plates and difficult to measure experimentally because of the complex structures of these plates. This study aims to investigate the RS in 2D plane weave aramid fiber composite plates using hole‐drilling technique coupled with moiré interferometry. A two‐step drilling method is proposed to solve the problems caused by the ‘peel up’ phenomenon, which facilitates the analyses of the obtained moiré patterns. The holes are deliberately selected at the intersection points of the symmetry axes of warp and weft yarns to obtain symmetrically released displacement fields. Moreover, finite element method calibration is conducted to measure RS using a model created based on the real structure of the woven composite. Based on the error analysis in numerical simulations, the less sensitive points are proposed for the RS calculation. The results show that the RS components of each specimen are compressive along the aramid yarns and tensile perpendicular to them. In addition, investigating of the influence of drilling depths on RS shows that RS decreases along the hole‐depth direction. Findings of this study are helpful for the manufacture and quality evaluation of woven aramid fibre composites.     

混合装配线防错系统的研究与开发

提出了面向复杂机械产品混合装配线的多Agent防错系统的模型，进行了相应的适应混合流水装配线的软硬件系统结构的研究。采用RS485总线控制系统的硬件配置，建立了工作站节点、数据采集、数据集成接口、智能决策等多Agent软件模块，形成了可适应装配产品变换的具有一定柔性、可扩展配置的防错系统。     

Pipeline Defect Detection Cloud System Using Role Encryption and Hybrid Information

Pipeline defect detection systems collect the videos from cameras of pipeline robots, however the systems always analyzed these videos by offline systems or humans to detect the defects of potential security threats. The existing systems tend to reach the limit in terms of data access anywhere, access security and video processing on cloud. There is in need of studying on a pipeline defect detection cloud system for automatic pipeline inspection. In this paper, we deploy the framework of a cloud based pipeline defect detection system, including the user management module, pipeline robot control module, system service module, and defect detection module. In the system, we use a role encryption scheme for video collection, data uploading, and access security, and propose a hybrid information method for defect detection. The experimental results show that our approach is a scalable and efficient defection detection cloud system.     

Design and Characterisation of a Temperature Compensated Relative Humidity Measurement System with On Line Data Logging Feature

A method of relative humidity (RH) measurement with on line temperature correction and data logging feature is described here. The RH sensor is a thermoset polymer capacitive type with on chip conditioning. Output voltage of RH to voltage converter is digitised using a 12-bit A/D converter and it is interfaced with an 8-bit microcontroller. Temperature correction of RH in real time is done using a temperature to digital converter interfaced with the microcontroller. The corrected data is displayed in a liquid crystal display and transmitted for on line monitoring and logging via RS232C. Calibration of the system is performed using standard saturated binary salt solutions. Accuracy and precision are found out. Hysteresis and ageing effect is discussed. The system performance is also compared with a dry/wet bulb psychrometer at different ambient conditions. The performance of the system in an industrial environment is presented.