PLC在大化肥散装仓库输送系统中的应用

应用PLC控制技术，改造大化肥散装仓库耙料机、卸料机和皮带输送自动控制系统，以解决该控制系统元件老化，故障频繁，维修量大的现象，达到提高自动化控制水平，确保装置安全、稳定、可靠、长周期运行的目的。     

化肥厂耙料机无线监控系统

PLC或智能仪表作现场控制器，工控机配置组态王软件作为上位机，实现数据联网共享，是目前工厂自动化的流行配置。结合耙料机工作的特点，设计了一套基于PLC和无线通讯模块EL705的无线监控系统，给出了控制系统的硬件配置及软件设计，介绍了该套系统在化肥厂耙料机上的应用。     

常见浓密机升耙结构介绍故障分析及其解决措施

浓密机是一种连续作业液固分离的大型专用设备,广泛应用于选矿治金、水处理等行业.浓密机在工作过程中随着池体底部矿浆的沉积、高浓度矿浆对旋转轴和耙架形成扭矩.当扭矩达到峰值时、浓密机需要提耙、以确保耙齿及旋转轴不受破坏.因此浓密机的升耙机构是确保浓密机正常运行的重要部件.以往浓密机多采用手动升耙的模式,不具备扭矩追踪功能、...     

耙料机集散控制系统的设计

以PLC或智能仪表作现场控制器，以工控机配置组态王软件作为上位机，实现数据的联网共享，是目前工厂自动化的流行配置，它和触摸屏技术相结合，可以适应恶劣的工作环境，改善工人的工作条件。本文介绍了此种控制技术在某化肥厂耙料机控制系统中的应用。     

基于PLC与力控的皮带运料虚拟监控系统设计

介绍了皮带运料系统PLC控制和力控组态软件设计过程,实现仿真现场工业控制要求。虚拟监控系统由上位机、通讯接口和下位机组成。上位机用力控组态软件制作虚拟监控界面,下位机下载PLC控制程序,通过通讯接口在上位机模拟皮带运料的运行情况。设计对工业现场的调试和研究有一定的参考价值。     

PLC在焦化厂运料小车自动控制系统中的应用

本文介绍了由下位机(PLC)和上位机构成的焦化厂运料小车自动控制系统.下位机(PLC)在现场可以进行系统控制、参数设置.上位机进行远程管理和打印,整个系统以下位机的工业级可编程序控制器为核心,实现自动化控制,该系统能确保运料的及时和可靠,降低系统的运行费用.     

浓密机生产过程综合自动化系统

针对浓密机生产过程工艺机理复杂,具有大滞后、非线性的特点以及给矿性质波动频繁、难以实现浓密机自动控制的难题,提出了由过程管理和过程控制两层结构组成的浓密机生产过程综合自动化系统。讨论了系统的结构、功能和浓密机底流浓度智能优化控制策略。实际应用结果表明,该方法实现了浓密机生产过程精细化,降低了浓密机压耙等生产事故,提高了浓密机生产效率,减轻了现场岗位劳动强度,实现了浓密机生产过程优化控制、优化运行和优化管理,取得了显著的应用效果。     

选煤厂取料机料耙液压泵站控制系统设计

针对目前选煤厂取料机料耙液压泵站电动机大多采用直接启动方式,液压油的温度检测采用模拟仪表实现,存在着对设备冲击大、油温检测精度不高、可靠性差等问题,提出了基于软启动器和PLC的新型液压泵站控制系统设计方案。该系统通过PLC采集液压泵站油温及设备运行状态,根据设定的工作模式对其进行控制,并可实时在线显示液压泵站运行状态、故障诊断报警信息,具有油温超限、滤油器堵塞、电动机过流等多种保护功能。     

堆料机控制系统中故障诊断技术的实现

为正确有效地处理传统的堆料机运行中的故障,提高系统自动运行的可靠性,以天津某港口煤炭输送系统设计为背景,在堆料机无人值守控制系统中应用专家系统技术,建立故障诊断信息系统。采用RSView32组态软件作为上位机监控软件,通过ControlNet网络以服务器/客户端的形式进行基于OPC技术的远程数据访问,实现对PLC工业现场的故障信号采集,并利用RSView32的VB接口来实现RSView32与故障诊断信息数据库的ADO通信。利用专家系统中专家知识对采集的故障信号进行分析处理并提出故障解决方案。实际运行结果证明,该故障诊断系统具有良好的实用性、有效性和开放性,对于出现的故障都能及时通过故障诊断信息数据库进行处理。     

基肥不同施用方法对水稻生长 及稻田周围水体污染的影响

研究表明，水稻基肥机深施及机前全层湿润施较耙面肥增产9～14%，氮肥的稻谷增产量提高55～76%，水稻对肥料氮素的当季吸收利用率提高4.4%～13.0%；水稻基肥(碳铵)机深施及机前全层湿润施用后，氮肥绝大部分进入土层，并迅速呈NH     

Deterministic behavior of temperature field in turboprop engine via shallow neural networks

Neural Computing and Applications - A study of machine learning approaches for temperature field (rake) prediction in a turboprop engine is presented. The potential of supervised machine learning...     

巧用FIX DMACS软件解决异种机型间的通讯

介绍了莱钢烧结厂生产调度指挥系统如何实现对1#烧结机Honeywell R1500优化控制系统和Modicon984系列PLC控制系统的数据通讯，解决了不同控制系统之间因网络协议不同而造成的通讯困难。     

测量耙对小尺寸发动机性能影响的研究

采用燃气发生器法进行小尺寸涡喷/涡扇发动机性能评价时,测量耙对截面参数和喷管特性的准确获取存在影响,最终导致发动机标准净推力准确度降低.为了减小上述影响,降低标准净推力计算误差,讨论了测量耙对发动机共同工作的影响,分析了测量耙对发动机喷管性能的影响,并基于数值仿真研究带耙/无耙喷管特性、测量耙损失特性,结合测量耙后截面...     

基于卡尔曼滤波的主动波浪补偿系统研究

针对船舶随涌浪进行的升沉运动进行较为深入的研究,旨在采用主动式波浪补偿解决耙吸式疏浚船耙管终端水平高度稳定问题。建立波浪补偿预测系统,通过运动参考单元测量船舶运动竖直方向速度和加速度,主控制单元根据所建立的数学模型结合卡尔曼滤波算法处理数据,通过执行机构调整绳索收放速度完成耙管终端控制补偿,使耙头水平高度在工作过程中保持稳定。所建立的波浪补偿预测系统具有自主学习能力,可以不断运用实测数据自我修正以提高精度,具有很高的实用价值。     

基于短时LS-SVM的GNSS铁路路基沉降监测数据分析研究

在GNSS(全球导航卫星系统)铁路路基沉降监测中,卫星信号受到周围环境的影响,同时实时监测中数据传输的不可靠性,导致监测结果往往有很强的不稳定性,有效地剔除粗差能提高GNSS监测的可靠性.鉴于最小二乘支持向量机有很强的非线性运算能力与数据拟合能力,建立短时最小二乘支持向量机铁路沉降数据预测模型,在监测中融合该模型,提高监测的有效性.分别运算该模型对山西中南部铁路通道重载综合试验地的3个监测点进行了分析处理,结果表明融合短时最小二乘支持向量机的预测模型有效抑制了GNSS监测中的离散误差,提高了GNSS监测系统的可靠性与稳定性,为铁路路基沉降监测提供了更为有效的手段.     

Machining of aerospace titanium alloys

The performance of PCBN (AMBORITE*) and PCD (SYNDITE) has been compared with that of coated tungsten carbide tool currently being used to machine titanium aerospace alloy. Tests confirm that SYNDITE gives a better surface finish, longer tool life and more manageable swarf than other tools. In addition, the “quick-stop” technique establishes that, for all three cutting tools, a layer is formed between the rake face and the underside of the emerging chip which has a fundamental effect on cutting and wear mechanisms.     

新一代投币机的研发

手机支付作为尚未完全开发的新兴商业结算支付服务已引起电信、金融、IT各界的共同关注.投币机如何通过技术改造赢得新的契机,已成为业界的重要课题.对IC卡、投币机、手机支付技术作了简单的介绍,并分析了各种支付方式的优缺点,总结了未来新一代投币机研发的必要性和方向.     

A framework for modelling spatio-temporal informal settlement growth prediction

Many developing countries grapple with the problem of rapid informal settlement emergence and expansion. This exacts considerable costs from neighbouring urban areas, largely as a result of environmental, sustainability and health-related problems associated with such settlements, which can threaten the local economy. Hence, there is a need to understand the nature of, and to be able to predict, future informal settlement emergence locations as well as the rate and extent of such settlement expansion in developing countries.A novel generic framework is proposed in this paper for machine learning-inspired prediction of future spatio-temporal informal settlement population growth. This data-driven framework comprises three functional components which facilitate informal settlement emergence and growth modelling within an area under investigation. The framework outputs are based on a computed set of influential spatial feature predictors pertaining to the area in question. The objective of the framework is ultimately to identify those spatial and other factors that influence the location, formation and growth rate of an informal settlement most significantly, by applying a machine learning modelling approach to multiple data sets related to the households and spatial attributes associated with informal settlements. Based on the aforementioned influential spatial features, a cellular automaton transition rule is developed, enabling the spatio-temporal modelling of the rate and extent of future formations and expansions of informal settlements.     

Electromyography of spinal and abdominal muscles during garden raking with two rakes and rake handles

Fifteen young normal subjects (4 males, 11 females) participated in the study. They were required to assume a staggered upright posture with left leg leading in front of a 75 × 75 cm raking box with 20-cm deep evenly distributed dry and wet sand and dirt. The subjects raked using a pulling and pushing action and a 60 cm stroke length at a self-selected optimum pace with a normal straight handled rake and with a rake with a modified handle. The handle modification consisted of three curvatures of 50, 60 and 50°, with an effective rake length of 150cm. While the subjects performed the raking their EMG was recorded from erectores spinae at L₁ and L₃ levels, external obliques and rectus abdominis bilaterally. The pulling activities with both rakes generated significantly different EMGs from pushing (p<0·01). The normal rake generated marginally higher activity compared to the modified rake. However, in pushing the modified rake generated much higher EMG activity than the normal rake (p < 0·01). The medium being raked and the moisture in it also had a significant effect on EMG (p < 0·02). On the basis of the results of this study, the normal rake was concluded to be a better rake.     

A mathematical model for simulating and manufacturing ball end mill

The performance of ball end mill cutters in cutting operations is influenced by the configuration of the rake and clearance faces in the ball component. From the mathematical design of a cutting edge curve, the rake face can be defined by the rake angle and the width of the rake face at each cross section along the cutting edge. We propose the fundamental conditions that must govern the engagement between the grinding wheel and the designed rake face in order to avoid interference while machining a ball end mill. As a result, a new mathematical model for determining the wheel location and a software program for simulating the generation of the rake face of a ball end mill are proposed. In addition, methods for grinding the clearance face in both concave and flat-shapes are introduced. The flute surface generated by a disk wheel during the grinding process is determined on the basis of a tangency condition. The results of the experiment and the simulation are compared to validate the proposed model.