基于MODBUS无线总线测控系统

本文提出了将工业现场总线ModBus通讯标准引入到nRF无线通讯技术中,组成ModBus无线总线测控系统.采用nRF905芯片作为无线收发模块的核心,主机和分机的信息交换以射频无线总线的方式实现,数据的无线传输遵循ModSus(RTU)通讯协议,采用半双工的工作方式,频率工作在ISM频段.按照ModBus协议的RTU模式,设计RTU消息帧的结构和格式,通过无线总线实现了主机与分机之间的信息传输和控制各个分机的工作.     

基于电阻应变式和无线遥测的喷水推进泵轴功率测量方法

根据电阻应变式的扭矩测量和霍尔式转速测量方法,设计了一套无线遥测的轴功率测量系统,对某高速巡逻艇的2台喷水推进泵的轴功率进行了现场测量。测试结果表明,与主机输出参考功率值相比,测得的轴功率能满足实际工程的需求。     

基于CC2420的无线信号采集系统的设计与实现

针对现代无线设备发展需要,研发了一种由微机与ARMS3C2410系统为核心的无线信号采集系统,通过CC2420无线收发模块实现数据采集无线化,现场从机采集的数据通过无线信道传送到主机,主机通过RS232与上位机PC进行串行通信,实现对设备的无线智能调控。实验证明该系统结构简单、传输可靠和可扩展性好,满足实际测试场合的需要。     

基于虚拟仪器的水管道泄漏检测定位系统的实现

摘要基于虚拟仪器的水管道泄漏检测定位系统,其检漏与定位分别采用声发射检测法和互相关分析法.硬件由一台主机、一台主无线数传机、多台从无线数传机和数据采集卡等组成.软件编程包含数据分析处理、数据通讯、结果显示查询、系统配置等模块.系统在实际应用中取得了良好的效果.     

组态王软件在热媒炉监控系统中的应用

一热媒炉控制系统及网络构成 控制系统采用PLC和上位机方式实现热媒炉自动控制功能。PLC与上位机采用OMRON公司Controller LINK方式通信，构成同级网络结构。上位机使用热媒炉组态软件组态人机界面，画面美观、交互性强。控制系统采用两台上位机可实现双机热备．一台为主机．一台为从机。主、从机采用TCP／IP协议构成局域网，从机适时从主机获得数据进行数据刷新。正常运行状态中，只有主机可下发操作指令，从机只具有显示功能：当主机运行中出现故障，系统会自动将从机切换为主机，代替原有主机实现下发操作指令。当任意一台PLC与上位机通信出现故障时，在上位机报警画面中会出现响应的报警文字提示。当故障主机排除故障恢复正常，系统会自动将主、从机切换回原始状态。系统运行时，在界面左上角会有登陆用户名、操作权限、本机状态指示。     

基于ARM及CAN总线的自动化喷雾降尘系统设计

介绍了综采工作面采煤机尘源跟踪喷雾降尘系统的实现,阐述了基于ARM嵌入式系统的主分机软硬件设计方法,通过采煤机上安装的红外发射传感器和支架上的红外接收传感器对采煤机实现定位,通过安装在支架上的电动球阀进行喷雾降尘,整个系统由主机来控制并通过TFT真彩LCD液晶屏来实时显示系统工作状态,主机和分机之间通信使用CAN总线。     

基于C#的多功能电能表校准软件设计

多功能电能表在配电系统中应用广泛,其计量的准确度对企业管理和考核至关重要,因此在设计多功能电能表时需要对其进行校准,满足一定应用等级。常规的多功能电能表校准方法是以电能脉冲校准为主,现提出一种基于C#和功率校表法的多功能电能表校准软件设计思路,采用串口进行通信,波特率可配置,同时可校准多台多功能电能表,最多可同时支持18块多功能电能表,通过校准后多功能电能表精度可达0.2级。     

714S天气雷达主控分机常见故障检查

714S天气雷达是一种固定式的S波段气象专用雷达。本文主要介绍了其主控分机系统,重点阐述了系统的智能故障检测功能,并对主控分机系统常见故障的处理进行了详细的解析,同时指出了检查主控分机故障时的注意事项。     

基于无线配置重触发的力学传动参数测试系统设计

为了实时测试履带式车辆运动状态下的力学传动参数,提出将存储测试技术和ZigBee无线通信技术相结合,设计一种可无线配置和多次重触发的力学传动参数测试系统。系统由无线手持终端、无线中继和多个测试单元组成,所有设备通过无线方式组成树形网络。通过设计通信编码,实现对各测试单元的无线配置、统一触发、点名触发等功能。无线配置可以实现对各测试单元编号、采样频率选择、多次触发等功能。各测试单元的配置信息存储在测试单元MCU内部Flash中,断电后数据不丢失。实验结果表明系统工作稳定可靠,无线配置与多重触发显著提高了工作效率。     

智能舞台分布式控制式系统的应用

针对国外舞台控制系统一般采用工控机加PLC协作组成,价格昂贵,制约了国内需求。本文开发了一台智能舞台控制系统,该控制系统由多片单片机组建一个分布式控制,由主机协调多个分机子系统共同完成信号的采集、分析和处理。该控制系统简单,能合理、高效、可靠地完成整个舞台灯光及机械的协调工作。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.