PLC实验系统构建模式研究

通过研究3种PLC实验系统构建模式的搭建方法,分析各自运行特征,比较各自缺点,搭建了1种基于INSPEC平台的三菱PLC虚拟实验系统。在同1台PC上实现了PLC程序的编写、虚拟PLC的运行、虚拟被控制对象,并实现了它们之间的通讯和仿真。在此系统上能完成PLC控制的程序设计、运行调试、过程监控,是一种合理的实验系统构建模式。     

物料混合PLC控制系统综合实验案例设计

为解决现代电气控制技术实验装置成本高、结构复杂,以及学生缺少工程实践背景等问题,利用虚拟仿真技术构建PLC仿真实验平台,探索虚拟仿真与传统硬件相结合的实验教学方法。选择工业控制领域典型的物料混合控制系统作为教学案例,设计一种虚拟交互式PLC物料混合控制系统。案例教学应用结果表明,基于虚拟仿真技术的案例教学设计无需实际物理控制对象便可实现对PLC 控制程序的调试与仿真运行,节约了设备成本,激发了学生学习兴趣,较为全面地锻炼了学生的PLC综合应用能力。     

触摸屏仿真在PLC课程实践教学中的应用

文章针对PLC实践教学中遇到的一些问题,提出了利用触摸屏仿真界面模拟PLC的控制对象,结合PLC仿真软件,构建基于PC的纯软件PLC虚拟实验环境,并通过教学实例详细给出了实验仿真环境的构建方法和仿真过程。教学实践表明,该方法操作便捷,调试方便,利于学生掌握有较大推广价值。     

基于Unity3D的PLC教学实训平台研究

针对各高等院校PLC教学实训平台的不足,为满足学生在各种应用场所都能调试PLC程序的需求,应用虚拟现实技术,开发了一个PLC半实物虚拟仿真实训平台。平台由可编程控制器、通信模块和虚拟场景组成,采用3Ds Max对场景和设备进行建模,V-Ray渲染器对模型进行渲染,通过Unity3D三维引擎开发平台完成虚拟场景构建,通过通信模块实现PLC与虚拟场景的通信。经过多个虚拟场景的控制实验测试,平台可稳定运行。学生能够实时高效地编写并调试程序,直观感受被控对象的运行,增强现场体验感,加深对PLC的认识,降低了同程度下的教学成本。     

虚拟PLC编程技能训练系统分析及教学应用

对当前PLC教学中存在的问题进行了分析,在此基础上引入了虚拟现实技术的教学思想,设计了虚拟PLC编程技能训练系统,对学生的PLC编程技能进行训练,让学生按照实际的控制要求进行仿真运行和调试,以利于更好地理解与掌握PLC。     

PLC虚拟实验室的研究与建设

介绍了3种PLC实验系统,分析了各自的优缺点,并以“液体混合装置控制”实验为例,重点介绍了基于三菱GX、GT系列软件的PLC虚拟实验室的建设方案.在PLC虚拟实验室只需计算机和相关软件就可以完成PLC程序设计、运行调试、过程监控等实训内容,是一种廉价、高效的实训系统.     

基于单片机的PLC虚拟负载实验系统的研究

PLC课程实践性强,为了达到良好的教学效果必须配备实验装置进行大量的实践训练。PLC的控制对象变化多样,想要对每种控制对象都开发实物实验装置不仅不现实,而且花费较大。利用计算机仿真软件进行虚拟仿真实验,虽然可以解决PLC实验教学中进行实物实验困难较大的问题,但不涉及硬件接线调试,对学生工程能力的培养造成缺失。针对上述情况,设计了以单片机为核心的虚拟负载实验装置,借助组态软件丰富的资源,可构建出形象逼真的控制模型,同时利用单片机设计的硬件接口电路实现硬件接线方面的训练。实践表明,这种软硬件结合的实验装置对PLC.的实践教学效果明显。     

基于MCD的爆震轴类零件检测维修线虚拟调试仿真实验

数字孪生技术的发展可以实现虚拟环境下的PLC控制仿真，该文针对爆震轴类零件检测维修线在现场实物调试过程中调试周期长、成本高、效率低、风险大等问题，以火炮轴类零件为工作模型，设计了一种基于MCD的个性化虚拟调试仿真实验。首先基于MCD平台对火炮轴类零件检测维修线模型完成功能属性的定义，再通过PLCSIM Advanced软件建立TIA Portal内PLC程序与MCD模型的连接，最后在TIA Portal内用虚拟触摸屏控制模型的运动。该虚拟调试实验验证了MCD模型通过PLCSIM Advanced实现虚拟PLC的控制的有效性，为火炮轴类零件检测维修线的调试提供了新思路。     

虚实结合的大型设备PLC实验系统设计与开发

以常用机电设备电梯为实验对象,开发了虚实结合的大型设备PLC实验系统。系统的上位机采用组态王虚拟大型设备运行、下位机采用真实PLC。该系统可逼真地模拟大型设备运行过程,当连接真实设备时,能实现监控且操作简单。它能够满足众多学生在实验室进行PLC控制大型设备的实验,实现面向大型设备的PLC控制实验进课堂的需求。     

基于OpenGL的交互式PLC虚拟实验系统

介绍一种基于OpenGL的交互式PLC虚拟实验系统。该系统在VisualC++平台上应用OpenGL技术建立真实可控的三维动画模型,并用计算机仿真技术开发了软PLC。最后,建立了软PLC和三维模型之间的连接,使软PLC按程序控制动画模型的运动,实现虚拟控制过程的仿真。     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

Social and Cultural Influence on Word Meaning

Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language.     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

Inequalities for inscribed simplexes

The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.