VIRTUAL PROCESSING OF LASER SURFACE HARDENING ON AUTOBODY DIES

A new method of collision-free path plan integrated in virtual processing is developed to improve the efficiency of laser surface hardening on dies. The path plan is based on the premise of no collision and the optimization object is the shortest path. The optimization model of collision-free path is built from traveling salesman problem （TSP）. Collision-free path between two machining points is calculated in configuration space （C-Space）. Ant colony optimization （ACO） algorithm is applied to TSP of all the machining points to find the shortest path, which is simulated in virtual environment set up by IGRIP software. Virtual machining time, no-collision report, etc, are put out atter the simulation. An example on autobody die is processed in the virtual platform, the simulation results display that ACO has perfect optimization effect, and the method of virtual processing with integration of collision-free optimal path is practical.

Event-driven process execution model for process virtual machine

Current orchestration and choreography process engines only serve with dedicate process languages.To solve these problems,an Event-driven Process Execution Model(EPEM) was developed.Formalization and mapping principles of the model were presented to guarantee the correctness and efficiency for process transformation.As a case study,the EPEM descriptions of Web Services Business Process Execution Language(WS-BPEL) were represented and a Process Virtual Machine(PVM)-OncePVM was implemented in compliance with the EPEM.

Simulation Based Energy-resource Efficient Manufacturing Integrated with In-process Virtual Management

As energy efficiency is one of the key essentials towards sustainability, the development of an energy-resource efficient manufacturing system is among the great challenges facing the current industry. Meanwhile, the availability of advanced technological innovation has created more complex manufacturing systems that involve a large variety of processes and machines serving different functions. To extend the limited knowledge on energy-efficient scheduling, the research presented in this paper attempts to model the production schedule at an operation process by considering the balance of energy consumption reduction in production, production work flow （productivity） and quality. An innovative systematic approach to manufacturing energy-resource efficiency is proposed with the virtual simulation as a predictive modelling enabler, which provides real-time manufacturing monitoring, virtual displays and decision-makings and consequentially an analytical and multidimensional correlation analysis on interdependent relationships among energy consumption, work flow and quality errors. The regression analysis results demonstrate positive relationships between the work flow and quality errors and the work flow and energy consumption. When production scheduling is controlled through optimization of work flow, quality errors and overall energy consumption, the energy-resource efficiency can be achieved in the production. Together, this proposed multidimensional modelling and analysis approach provides optimal conditions for the production scheduling at the manufacturing system by taking account of production quality, energy consumption and resource efficiency, which can lead to the key competitive advantages and sustainability of the system operations in the industry.

Imperfect preventive maintenance for numerical control machine tools with log-linear virtual age process

Based on the log-linear virtual age process, an imperfect preventive maintenance policy for numerical control(NC)machine tools with random maintenance quality is proposed. The proposed model is a combination of the Kijima type virtual age model and the failure intensity adjustment model. Maintenance intervals of the proposed hybrid model are derived when the failure intensity increase factor and the restoration factor are both random variables with uniform distribution. The optimal maintenance policy in infinite time horizon is presented. A numerical example is given when the failures of NC machine tools are described by the log-linear process. Finally, a discussion is presented to show how the optimal results depend on the different cost parameters.

Virtual Reality Based Process Integrated Simulation Platform in Refinery:Virtual Refinery and Its Application

With the combination between system simulation and virtual reality,we have established an integrated virtual refinery simulation platform,and analyzed the overall design and principal architecture.This paper introduces a simulation algorithm about a refinery based on virtual reality,and explains how the algorithm can be applied to the virtual refinery integrated simulation platform in detail.The virtual refinery simulation platform,which consists of a three-dimensional scene system,an integrated database system and a dynamic-static simulation system,has many applications,such as dynamic-static simulation of key process unit used as process control and oil tank blending simulation for scheduling.With the visualization and human-computer interaction for acquiring production and process data,this platform can provide effective supports on staff training related with monitoring,control and operation in refinery.Virtual refinery can also be web published through the internet and it is helpful for the distance training and education.

Reliability modelling based on dependent two-stage virtual age processes

This paper proposes reliability and maintenance models for systems suffering random shocks arriving according to a non-homogeneous Poisson process.The system degradation process include two stages:from the installation of a new system to an initial point of a defect(normal stage),and then from that point to failure(defective stage),following the delay time concept.By employing the virtual age method,the impact of external shocks on the system degradation process is characterized by random virtual age increment in the two stages,resulting in the corresponding two-stage virtual age process.When operating in the defective state,the system becomes more susceptible to fatigue and suffers from a greater aging rate.Replacement is carried out either on failure or on the detection of a defective state at periodic or opportunistic inspections.This paper evaluates system reliability performance and investigates the optimal opportunistic maintenance policy.A case study on a cooling system is given to verify the obtained results.

Design and Research on Virtual Display of Whole Process Mechanization for Rice Production in Cold Region

With the development of society,the virtual reality technology and multimedia technology have been applied to modern large-scale agriculture. The paper describes the design ideas for animation display of mechanized rice production in cold region,and elaborates the design of major part of each scene. By animation display,we can know about the whole process of rice production,as well as the benefits of mechanized operation.

Virtual Mold Technique in Thermal Stress Analysis during Casting Process

It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. Moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

基于万维引擎自主开发虚拟仿真实验——以流体阻力实验为例

化工类实验具有危险且复杂多变的特点。文章以流体阻力实验为例,阐述了基于万维引擎的网页版虚拟仿真实验的自主开发过程,包括实验设备建模和渲染、教学模块设计、软件功能开发、逐项功能测试等内容。所开发的虚拟仿真实验实现了虚拟实验与现场实验从设备到内容的紧密关联,契合真实的实验教学过程,为国内外学生提供了在线学习与操作练习的机会,同时也是开展线上线下混合式实验教学的重要基础。

电化学加工虚拟仿真实验建设与应用

电化学加工现有实验教学以模型演示和装备讲解为主,学生自主学习和实验教学效果较差.基于此,开发完成了"电化学虚拟仿真实验"教学项目,营造逼真的虚拟实验环境,模拟真实电化学加工成材成形过程.学生可以根据需要选择合适的加工方式,掌握具体操作过程和工艺参数,在沉浸式环境下弄清电化学加工由"无形反应"到"有形实物"的工艺过程实质.

矿物加工虚拟仿真实验教学建设及实践——以中南大学矿业学科为例

针对新时代矿业行业对专业人才的要求,以培养学生全周期工程思维和提高其工程胜任力为目标,采用虚拟仿真的教学手段,突破矿产资源加工过程中高温、高危、高成本等限制,解决传统教学无法开展全流程实验及生产极端工况操作等难题,将科研成果融入实验教学,有机融合数据库技术、虚拟仿真、专家系统、智能算法,让学生通过自主选题、自主探究学习、自主流程设计、自主设备搭建、自主调试运行,设计与资源特性相适应的工艺流程、生产设备及操作参数,实景体验工业生产过程异常工况,使其成为具有实干担当、开拓创新、国际视野和竞争力的矿业卓越人才。

新一代地面站测控数传通用处理资源池设计

随着我国在轨卫星数量和类型的日益增多,对地面站测控数传系统的通用性、扩展性提出了更高的要求。提出了基于云计算架构、采用通用硬件基础设施搭建测控数传通用处理资源池的思路,对资源池的总体架构、硬件组成、软件实现方法、系统运行流程等关键技术进行了详细阐述;搭建了原型样机进行技术验证。基于云计算架构的新一代测控数传通用处理资源池系统能够显著提高测控数传系统的使用效率,提升航天地面测控系统的可重构能力、可扩展能力和多任务多目标的适应能力。

虚拟仿真技术在机械基础加工实训教学的应用现状与发展趋势

虚拟仿真技术在机械基础加工实训教学中的应用对学生综合素质的提升产生了重要作用。首先梳理了虚拟仿真技术的发展现状,并分析了其在实训教学中的突破。接着,对虚拟仿真技术在机械基础加工实训教学中的应用与遇到的问题展开研究,并基于此提出了虚拟仿真技术应用于机械基础加工实训教学的发展思路。

基于私有云的高校数字化体育资源共享建模分析

传统资源共享建模方法传输较大资源数据块存在速率较低的问题,因此以解决该问题作为研究目标,提出了一种新的基于私有云的高校数字化体育资源共享建模方法。根据私有云计算技术,检索共享资源目录,完成高校数字化体育资源的聚类和存储操作,从物理存储和逻辑存储两方面对其进行虚拟化处理,判断其共享路径,以此搭建高校数字化体育资源共享模型,实现资源共享。实验结果表明,所设计的建模方法吞吐量大于两种传统方法,且资源数据块较大时,仍然具有较高的数据传输速率,实际应用效果更好。

集成电路工艺制程虚拟仿真实验设计

高校普遍存在难以建造完整的集成电路工艺线,导致工艺实验难以有效开展,在一些特殊情况(如突发疫情)下,原本建立的校企、校校合作方式开展的工艺实验难以实施等问题。针对存在的问题,以在功率集成电路中广泛应用的横向扩散金属氧化物半导体(LDMOS)器件为例,开展集成电路工艺制程虚拟仿真实验设计。基于半导体工艺计算机辅助设计(Sentaurus TCAD)虚拟仿真平台,完成LDMOS器件的结构设计、工艺设计、性能测试等实验环节,涵盖了集成电路从硅片选型到芯片成型的全流程工艺。

基于Unity3D的机床加工实训仿真系统

针对目前高校机械专业学生在机床加工实训当中普遍存在设备操作危险、实训加工设备不足且实训效果不佳的情况,本研究以工业机器人转运及机床加工阶梯轴过程为研究对象,借助Unity3D开发平台设计出虚拟现实机床加工实训仿真系统。运用SolidWorks与3DsMax软件完成了三维建模,运用Photoshop软件对模型进行贴图和UI界面设计。使用Unity Animation组件完成阶梯轴生产加工过程动画,利用Unity3D配合C#语言实现了场景漫游、视角定位切换、虚拟手抓取等功能,最终完成并发布了机床生产加工仿真实训系统。该系统展示了阶梯轴在机床上的加工过程,实现了加工过程的可视化及进程控制,同时具备人机交互功能,选择使用虚拟手替代工业机器人完成上料,控制视角转移观察加工过程,能够极大的提高学生的实训兴趣,提高实训效率,改变传统生产加工实训方式。

传统钩编花样设计与工艺虚拟仿真实验

针对钩编花样设计与工艺实验教学中存在的制作周期长、打样成本高、成品产出效率低、学生参与度低的问题,探索应用现代信息化技术和虚拟现实技术,构建以学生为主体、问题为导向、以虚促实为原则的钩编花样设计与工艺虚拟仿真实验。设计3个实验阶段、4个实验模块和13个主要交互性实验操作步骤,以期打破时空限制,提高实验效率和质量,激发学生学习和创作热情,提升学生实验操作能力、自主学习能力和创新能力,推动高校教学改革和发展,培养应用型专业人才。

数字图像处理及应用虚拟仿真实验平台设计

针对数字图像处理及应用实验教学的需要,结合当下图像处理技术的热点应用,利用虚拟仿真技术、交互操作等信息化手段进行实验教学,设计并开发了数字图像处理及应用虚拟仿真实验教学平台。实验教学平台包含交通标志数字图像处理、图像分类、图像识别、视频处理、自动驾驶应用等5个虚拟仿真实验教学资源,共13个交互实验步骤。该平台特色显著、虚实结合,达到了良好的教学效果,为“新工科”背景下的虚拟仿真实验教学提供有益的参考。