计算机综合制造系统优化设计的研究

在等效工作站的基础上,并以中途不丢失工件为前提,对串联CIMS进行了优化设计的研究.分别就首站前和末站后有无缓冲区、中间缓冲库容量是否一致、工作站是否可靠和总资源约束等不同的情况下,讨论了系统优化设计问题,得出了精确的分析解.最后列举一个计算实例,阐明所提出的方法在工程设计中的应用.     

焦化厂煤气鼓风机机械保护系统的改造

本文主要介绍如何利用美国本特利内华达3500机械保护系统对煤气鼓风机进行技术改造，通过设计选型和安装调试的经验，提示在设计、安装调试中应该注意的问题。同时也叙述了系统的一些特点，以及系统功能在安全生产中的作用：     

炉水协调磷酸盐-pH处理自动控制原理及自动加药系统优化设计

以纯磷酸盐理论为基础,推出了适于高压、超高压汽包锅炉炉水协调磷酸盐-pH处理的数学模型,介绍了基于上述数学模型而研究开发的炉水协调磷酸盐-pH自动控制加药系统的加药原理,提出了5种设计方案,并进行了比较,最终指出最佳性能价格比的首选方案.     

基于ERP的卷烟制造企业智能信息系统

结合卷烟制造企业的背景和需求,分析了该行业的特点,应用ERP原理,设计并实现了适应烟厂管理特殊要求的智能信息系统;并依照系统总体设计日标和原则,给出了相应的系统结构与功能模块;系统可提供支持用户决策和全面管理的强大功能,实现企业组织流程的整体优化。     

雾化喷头性能测试实时监控系统的设计

根据对控制要求的分析,采用西门子PLC+MCGS组态技术来实现恒压、恒流监控功能;PLC用来采集传感器的输入/输出信号,并且通过PLC闭环PI控制的方式实现对QSVY型电动调节阀的连续控制,达到管道出口参数恒定的目的;PLC通过各种传感器测量各设备的运行状态,并把信息传送给上位机,上位机组态软件通过监控画面把设备的运行状态变化用动画、曲线形式表现出来;试验时,采用美国喷雾系统公司的XR-TEEJET11002型喷头进行控制系统的控制性能分析;当K=0.3,T=0.04时,过程值与设定值曲线基本重合,最大控制误差为0.01Mpa,且输出几乎不振荡,并可实现压力0.01Mpa的调节精度,流量1L/min的调节精度,说明本设计系统可靠。     

基于核主元分析的卷烟致香成分相似性评价

卷烟产品中致香成分的种类和含量是区分卷烟风格的主要因素。针对致香成分指标种类繁多的特点,本文提出一种基于多元统计分析的致香成分分析方法。首先采用核主元分析方法将卷烟产品的63种致香成分指标数据映射到二维特征空间,且特征数据的原始信息含量不低于95%;然后引入类间离散度指标分析和评价不同品牌卷烟产品的致香成分相似性。分析结果表明,采用本文方法获得的9个品牌卷烟产品的致香成分相似性分析结果与传统经验评吸结果一致。该方法为传统的卷烟风格分类方法提供了有效的理论支持。     

制丝线加香加料系统的问题及改进方法

针对目前卷烟企业制丝线加香、加料系统普遍存在的问题,从设备选型、控制算法进行分析,提出改进方法。     

基于PLC的卷烟自动分拣系统

卷烟自动分拣系统在烟草工业中占举足轻重的作用.介绍了基于PROFIBUS现场总线和S7-300PLC的卷烟自动分拣系统,以及系统的组成与设计方法.该控制系统运行良好可靠,其综合效益十分明显.     

基于WINCC的卷烟生产监控系统

基于西门子PLC和WinCC(V6.0),设计并实现了卷烟厂制丝设备排潮/除尘、卷接机组集中式工艺风力/烟丝输送除尘自动监控系统.本文通过一个实例,介绍了系统的硬件组成、网络结构和软件设计思想,论述了系统的主要功能.实践表明,该系统界面友好,操作方便,安全稳定,符合现场工作要求,达到了预期的设计效果.     

基于改进蜂群算法的建筑管路布局约束多目标优化设计

针对建筑空间管路布局约束多,难以定量分析设计中多指标冲突的问题,提出一种基于改进蜂群算法的建筑空间管路布局优化设计方法。首先,构建三维建筑管路布局模型,以管路总能量值（长度、弯头数量等）、管路避障等为优化目标,构建多约束目标函数。然后,针对传统蜂群算法容易陷入局部最优和难以保证种群多样性的问题,提出基于Levy飞行策略的改进人工蜂群算法,进行多约束下的建筑管路布局优化求解。所提算法在雇佣蜂的搜索阶段,引入Levy飞行策略,根据上一蜜源的能量值及迭代次数自适应调整更新步长,从而提高全局搜索能力并加快收敛速度。实验表明,所提方法比传统蜂群算法不仅在整体探索能力上得到了提升,而且得到的管路路径长度更短、弯头更少、能量值更低,能够满足真实建筑环境中理想管路自动布局的要求。     

离散系统最速控制综合函数

针对自抗扰控制技术中的fhan()函数,指出其只是离散系统最速控制综合函数的一种简化.详细推导了离散系统真正的最速控制综合函数——fsun(),完善了自抗扰控制技术的理论框架.理论分析和数值仿真表明,采用fsun()函数后的二阶离散系统,状态变量达到稳态时位置和速度曲线均不会出现超调,且达到稳态时所用的步数少于函数fhan().     

A decision-making framework model for design and manufacturing of mechanical transmission system development

Knowledge-based systems are proving to be a powerful tool with great potential for developing intelligent design support environments to improve quality of products and reduce product development costs by eliminating or minimizing many of the trial-and-error iterations involved in product development. This article describes an approach towards the development of intelligent design support environments for mechanical transmission systems, along with implementation details of a distributed knowledge-based gearing design and manufacturing system that is deployed over the Internet. The system embodies the various tasks of the design process, with modules that address: performance evaluation, process optimization, manufacturability analysis, and provides reasoning and decision-making capabilities for reducing the time between gear tooth creation, detailed design and final production. This methodology is highly desirable in that it is able to simulate real working conditions, evaluate and optimize the design effectively, prevent designers from time-consuming iterations and reduce long and expensive test phases.     

微电子天平称重及造表系统的研究与设计

为解决工业领域微电子天平数据采集及造表问题,设计一种基于C＃线程委托和Excel编程接口的称重及造表系统。在阐述数据采集及表格生成原理的基础上,给出系统总体框架,重点阐述不同参数条件下多天平的同步录入问题及串口复用问题,提出一整套带有趋势图的批量Excel表格生成方法。项目实践及实际应用结果表明,该软件系统能够完成用户对多天平数据采集及录入的要求,快速、准确生成规范的数据趋势报表,提高了企业的生产及质检效率。     

机械设计领域的命名实体识别研究

命名实体识别技术在自然语言处理技术中占有重要的地位,通用的方法不能很好地解决机械领域的识别问题。基于字符串之间紧密相邻程度等统计特征,定义不同词之间紧密相连的程度,从而识别机械领域的领域词。通过计算特征值,用逻辑回归的方法确定相邻字串的紧密相邻程度,从而发现新词。该方法对比通用的方法准确率和召回率得到了提高,更好地识别机械领域的领域词。     

The role of design for manufacturing in system integration

The costs of “over design” to build in recovery tactics for poor design-production match are substantial. Design for manufacturing can greatly improve the design-production match and enhance manufacturing system integration. A model of manufacturing integration is given which emphasizes three major parameters: (1) Corporate planning, (2) Capacity, and (3) Productivity. The model enables an assessment of overall manufacturing system integration. Methods for gathering the required data and analyzing the data to supply the system integration model metrics are given. Design for manufacturing is shown to significantly impact system capacity, production control, and effectiveness of manufacturing system integration.     

A decision support system for cellular manufacturing system design

With the growth of competitive pressure in the global markets, there has been an increase in demand in industry for cellular manufacturing systems (CMSs) in order to improve productivity and process flexibility. The design of CMSs for industrial applications is a complex and knowledge intensive process as it involves the consideration of many factors including production data and process characteristics. This paper describes the development and implementation of a decision support system for the feasibility and conceptual design of CMSs. The system is based on the knowledge-based system approach, and is able to make recommendations of system feasibility, cell formation techniques and cell types. A case study is also presented to demonstrate the capability of the decision support system.     

An integrated form-feature-based design system for manufacturing

Much of the knowledge that is applied in or communicated between design and manufacturing activities is primarily shape based or shape indexed. Previous attempts to acquire and organize shape knowledge have been mostly concentrated on feature recognition from solid models, group technology (GT) coding schemes, and feature-based modeling. This paper presents the development of an efficient form-feature-based modeling system, and addresses the important issue of utilizing feature information for manufacturing, which has not been extensively discussed by previous work. In this paper we first present a Euler operator-based approach for efficient and effective form-feature encoding and manipulation in a feature-based design environment. Subsequently, a hybrid representation scheme called enhanced CSG tree of feature (ECTOF), which integrates feature model with solid model in a tree structure, is discussed. A feature interference resolution methodology to maintain the correct and consistent feature information in an ECTOF is also deliberated. Finally, we present a machinability-checking module, which employs global accessibility criteria to analyze a feature's machinability on a three-axis machining center. By developing feature interference resolving and machinability testing techniques and integrating with an efficient feature-based design system, this research makes the development of an integrated feature-based design and manufacturing system possible.     

嵌入式设备上的文件系统优化设计

FAT32在Linux上的优化与实现是提高硬盘式嵌入式设备性能的关键因素。通过深入分析FAT32文件系统在Linux上的实现细节,针对性地提出了多种优化策略:Block机制实现优化、预读机制控制优化、Page机制改进等。最后给出了一个实际系统的性能优化比较。     

Comparison of layered cellular manufacturing system design approaches

In this study, a mathematical programming approach is proposed to design a layered cellular manufacturing system in highly fluctuated demand environment. A mathematical model is developed to create dedicated, shared and remainder cells with the objective of minimizing the number of cells. In contrast with classical cellular manufacturing systems, in layered cellular systems, some cells can serve to multiple part families. A five-step hierarchical methodology is employed: (1) formation of part families, (2) calculation of expected cell utilizations and demand coverage probabilities, (3) specification cell types as dedicated, shared, and remainder cells, (4) simulation of proposed layered systems to evaluate their performance with respect to average flowtime and work-in-process inventory, and (5) statistical analysis to find the best layered cellular design among alternatives. It is found that designs with higher number of part families tend to have less number of machines. Similar results are also observed with respect to average flowtime and work-in-process inventory measures. The results are also compared with a heuristic approach from the literature. None of the approaches is dominant with respect to all of the performance measures. Mathematical modeling approach performs better in terms of number of machines for most of the alternative designs. However, heuristic approach yields better average flowtime and work-in-process inventory for most of the designs.