基于工作流引擎的智能车间综合自动化系统研究

随着现代车间向智能化方向发展,基于工作流对车间综合自动化系统进行建模和研究也变得越来越重要和困难。该文基于访问控制技术对基于工作流的企业综合自动化系统进行设计,设计其工作流引擎的应用模型,给出了自定义表单的工作流系统结构。通过智能数字化工厂硬件平台阐述了现代智能车间综合自动化系统的实现过程,该系统包括工件仓储管理、数字化制造加工、自动化输送、信息管理等一系列自动化过程,可满足智能数字化工厂理念并展示了基于工作流的企业综合自动化系统的优越性。     

基于柔性化工作流的设备管理系统设计与开发

为扩大设备管理系统的应用范围,满足企业无纸化办公需求,解决复杂审批流程问题,提高设备管理效率,设计和开发出了基于柔性化工作流的设备管理系统。分析了系统的功能模块和业务需求。根据设备管理审批流程的特点,设计了柔性化工作流的六种工作模式,采用了特征建模技术建立工作流信息模型和工作流实例模型,结合SOA服务思想,构建流程总体框架,提供了设备流程化管理平台,对业务单据和流程数据进行有效跟踪,增强了设备的有效利用率,提高了设备管理的灵活性和动态性,并在企业中得到应用。     

基于工作流的主动信息共享体系结构

针对目前企业信息与业务过程分离的静态信息共享模式，提出基于工作流的主动信息共享系统框架，依托工作流管理系统平台，实现了以主动提供信息为主、高效信息查询为辅，推拉结合的信息共享机制，使相关信息伴随企业业务过程的推进而实现高效共享。以A6ent为主要实现技术建立了基于工作流的主动信息共享原型系统，详细介绍了系统运行机制与实现结果。     

参数化工作流动态建模及其在PDM系统中的应用

为提高工作流对动态不确定因素的处理能力，提出了参数化工作流动态建模方法。通过多个参数化模型的实例，建立实际的业务过程模型；同时为了控制和导航整个业务过程，提出了活动控制参数规则、多于模型实例之间的流转关系控制策略和基于管理角色的人为控制策略。为了实现该动态建模方法，工作流管理系统需要对工作流管理联盟的规范作较小程度的扩充。实际应用表明，这种方法是有效和可行的。     

基于工作流的制造企业应用集成框架研究

在阐述工作流定义、工作流管理系统的组成和应用的基础上 ,分析研究企业应用集成中的工作流关键技术 ,总结目前工作流建模、工作流分析、工作流执行和工作流互操作技术存在的不足 ,提出基于工作流的制造企业应用集成框架结构。这种基于工作流的制造企业应用集成既能有效实现PDM、ERP、SCM、CRM之间跨越时空、地域和供应链的信息集成 ,又能在人和应用间实现有效协同 ,最终实现系统的全局优化发展     

访问控制技术在企业公文流转系统中的应用研究

访问控制技术是实现信息安全的重要技术之一。本文详细分析了现有访问控制模型的优点和缺陷;并按照某公司业务流程,分析了该企业公文流转系统的访问控制需求,选择基于任务和角色的访问控制模型用于该企业公文流转系统中,并实现以满足实际应用需求。     

基于Agent的分布式工作流控制模型研究

为了实现虚拟企业的业务过程管理,引入智能体,设计了一种新型工作流控制模型.该模型利用任务执行智能体的信息传递,实现分布式工作流的动态划分;利用评估工作流引擎,实现对工作流中任务前置条件的评价.任务执行智能体所实施的工作流执行与控制算法,分两个阶段评价工作流的依赖,避免了不必要的依赖评价和信息发送,从而有效完成虚拟企业的分布式工作流控制.     

工作流模型可调度性验证与分析方法

实施工作流管理是支持复杂产品的设计、制造及销售等高度复杂工作流程高效运作的有效手段,而从理论上验证和分析相应工作流模型的正确性及合理性对工作流管理系统的成功实施有着重要的意义。在讨论了工作流模型在时间层次上需要考虑的各种时间约束的基础上,通过扩展时间信息到只描述过程逻辑的工作流网中来,给出了时控工作流网的概念。进而在给出了从一种包含时间信息的有向网络图到时控工作流网的模型映射方法之后,对基于时控工作流网的工作流模型可调度性验证与综合进行了详细的讨论。最后用一实例验证了其有效性。     

产品数据管理与企业资源计划系统间更改信息的集成与控制

提出了一种产品数据管理与企业资源计划系统间通用的更改信息描述方案与集成方法,以及基于工作流技术的更改信息控制策略。将产品数据管理与企业资源计划系统间集成的更改信息归纳为对象、层次结构和文档三类基本形式,形成了通用的更改信息表达方案。基于中性数据环境,实现了更改增值信息的共享与集成。将更改过程的相关信息划分为变更对象、更新对象和辅助对象,并利用工作流技术完成了过程间的推送、跟踪与信息发布,实现了对更改过程的控制,保持了更改产生的新版信息与原版信息之间的关联升级与关联继承性。通过实际的产品数据管理与企业资源计划系统中的实施与应用,实现了更改信息集成和控制方案,为产品数据管理与企业资源计划系统间更改信息集成与控制的研究应用提供了一条有效的解决方案。     

支持动态联盟的工作流管理

动态联盟构建不仅需要实现信息集成 ,而且需要实现过程集成 ,日益成熟的工作流管理技术为此提供了有效的支持工具。文中首先强调了工作流管理中知识的重要地位 ,提出了一个四视图 (过程、组织、资源和知识 )扩展工作流模型 ,并对动态联盟工作流管理四个视图分别进行了分析。最后给出了基于自治节点的工作流管理系统框架。     

基于集散控制技术的电厂干出灰系统设计

根据电厂干出灰控制系统的操作流程,设计出集散控制系统,重点解决了现场控制站与厂级信息监控系统的通讯问题,并完成了主控软件的编制。该系统的应用减轻了操作人员的强度,提高了效率和稳定性,其系统的建构方法为工业上类似流程控制问题提供了借鉴。     

基于XML/OPC的ERP/MES/底层控制集成系统研究

实时的信息管理是电子化制造模式的需要。分析和描述了ERP/MES/底层控制集成系统的信息流,建立了基于XML的ERP/MES/OPC共享信息组织结构,提出了利用XML网关进行XML信息校验、数据过滤和转换的方法,构造了面向OPC开放式软控制技术的MES/底层控制模型,实现系统间的信息集成和控制集成。MES作为ERP和底层控制的桥梁,使以天、周、月、年为时间因子的ERP系统达到实时。最后给出了一个基于该技术的自动装配线实验应用系统。     

Velocity measurement for two-phase flows based on ultrafast X-ray tomography

The ultrafast electron beam X-ray tomography scanner ROFEX is used for the investigation of multiphase flows. Its functional principle allows us to obtain sequences of cross-sectional flow images, which shows local attenuation properties of the flow. Hence, the X-ray CT images mainly reveal the shape and interfaces of flow constituents, such as gas, liquid and solids via their X-ray contrast. It is, however, more difficult to obtain velocity information from multiphase flows. In this article we discuss different methods to extract information on the velocities of particles or interfaces as well as for continuous phase. For disperse phase velocity measurement, e.g. in gas–liquid or gas–solids flows, we employ cross-correlation based techniques using two imaging planes. Apart from the standard cross-correlation technique we developed a method and algorithm, which is capable to identify identical bubbles in the two planes giving us a unique Lagrangian particle-related velocity information. Eventually we give an example of velocity measurement in the continuous liquid phase using an X-ray contrast agent.     

物与信息混合驱动的带返修生产系统性能分析

聚焦物与信息两流混合驱动的含返修闭环异步串联生产系统,在综合考虑加工设备和信息控制设备随机故障的基础上研究了生产和信息控制参数对复杂生产系统稳态性能的影响。基于工件加工与信息的交互作用关系,采用重叠分解法将该系统拆分成多个混合驱动的装配和拆卸子系统。建立了前向和反向递归迭代算法来估计系统稳态生产率。数值实验与工业缝纫机数字化生产线案例验证了迭代算法在识别系统瓶颈和估算系统稳态性能等方面的有效性。     

Water film thickness measurement system for oil-water pipe flow

A new technique development for high spatial and temporal resolution film-thickness measurement in oil-water flow is presented in this work. A capacitance measurement system is proposed to measure thin water films or local water fractions near to the pipe wall. The measurement system is based in a planar sensor which is flexible and can be placed close to and following the curvature of the inner wall of the tube. Experimental results of the capacitive technique showed that the system is able to measure film thickness between 400 μm and 2200 μm. Dispersed and core-annular flows were studied in a vertical 12-m-height glass pipe with 50.8 mm of internal diameter, using mineral oil (860 kg/m3 of density and 220 mPa s of viscosity) and tap water. Local time-domain signals and axial and circumferential distributions of water film thickness near to the pipe wall and 3-D images of water film are presented. The measured film thickness, obtained by the proposed technique, was compared with that obtained through a camera-based imaging technique and the agreement was good, with a deviation less than 20%. The new technique allows the observation and characterization of average interfacial topologies in separated flows, and high frequency phenomena related to dispersed flows that occur in liquid-liquid flow near the pipe wall.     

摩擦自激系统的分岔控制研究

研究应用Washout滤波器技术对摩擦系统自激振动的分岔控制.首先确定需要引入的Hopf分岔点,然后按Hopf分岔条件确定滤波器的线性增益和非线性增益系数,将系统的亚临界Hopf分岔变为超临界Hopf分岔,使受控系统产生的自激振动幅值大大降低.理论分析和数值仿真表明Washout滤波器法在分岔控制中的有效性.     

Rotating microchannel flow velocity measurements using the stationary micro-PIV technique with application to lab-on-a-CD devices

The measurement of microfluidic flows is an essential instrument to understand the governing physical mechanisms at small scales. This fact has motivated the adaptation of well-established “macroscale” experimental technics to deal with the specificities of microfluidic flows; a prominent example is the micro particle image velocimetry (micro-PIV) technique. In a different manner, the progress experienced by experimental techniques to measure flows in rotating frames has been more limited, with most studies concerned with macroscale turbomachinery applications. It turns out that the scale reduction in this field establishes a new and important flow class, known as centrigually-driven microfluidics, with application to lab-on-a-CD devices. However, the experimental characterization of rotating microflows has been, so far, limited to bulk flow measurements and/or visualization practices. For that reason, in this work, we propose extending the stationary micro-PIV technique to undertake quantitative, whole-field, velocity measurements inside rotating microchannel flow platforms. For this task, actual lab-on-a-CD prototypes are used. This work develops in two parts. First, we describe the most relevant changes in the micro-PIV equipment viewing the introduction of the test section rotation, namely: (i) hardware changes related to the micro-PIV/CD synchronization and (ii) software changes aiming at the preservation of the velocity measurement accuracy, through the removal of the circumferential velocity component. While this last step follows a well-known methodology, called image de-rotation, we propose tackling it in a new and automated fashion by means of the image registration method, whose implementation and advantages are explained in detail here. The second part of this work evaluates the capabilities of the modified micro-PIV technique by critically assessing the results of preliminary tests undertaken in dynamical regimes where rotation is dominant. Here, we present for the first time velocity profile measurements of centrifugally-driven microchannel flows, which display marked structural differences from classical stationary pressure-driven flows. The quality of these experimental profiles is further examined through comparisons with computational fluid dynamics simulations, based on the lattice Boltzmann method. Overall, this study indicates the effectiveness of the proposed micro-PIV system, which is able to accurately capture the most relevant physical features of rotating microfluidic flows over regions sufficiently far away from the walls. On the other hand, inside the boundary layers, the present micro-PIV measurements remain difficult to execute; the reasons for this limitation are discussed and clearly identified in the present preliminary studies, which pave the way for future studies in the field.     

Visualisation of gas–oil two-phase flows in pressurised pipes using electrical capacitance tomography

Electrical capacitance tomography (ECT) was used to image various two-phase gas–oil horizontal flows on a 7.62 cm (3 in.) pressurised test loop. ECT is a novel non-invasive technique for imaging mixtures of electrically non-conducting substances. One of its most promising applications is the visualisation of gas–oil flows. This work presents a series of imaging experiments using a pressure-resistant ECT sensor. By varying the oil and gas flow rates, different flow regimes were established in the test loop. ECT images were obtained for each case and compared with (a) the flow observed through a transparent section in the loop and (b) the prediction of the Taitel–Duckler flow map. The results confirm the suitability of ECT for imaging gas–oil flows.     

基于GPRS实现的远程数据采集系统

本系统中LP3500利用MODBUS通信协议和仪表通信，采用GPRSDTU模块为远程数据传输模块。依托GPRS网络，采集远程终端数据：响应主控室的一系列的遥测命令。利用Dynamic C程序使用uC-Ⅱ实现了LP3500核心模块采集仪表数据．GPS时间信患，处理相关的报警和控制信患。结果表明，运用该系统能成功地提取出仪表数据和GPS有用数据并通过GPRS网络响应主控室的命令。     

基于多代理的分布式车间控制系统的研究

基于多代理系统给出车间控制系统的体系结构 ,为车间控制系统引入管理代理、任务代理和资源代理 ,各个代理各尽其职 ,相互协调 ,保证了车间控制系统能够在动态的环境下正常运作 ;在分析控制系统中的任务类型后提出了各种任务集合的定义 ,在此基础上给出任务代理和资源代理交互协调的流程以及它们各自的运作流程。