Location layout design of aircraft parts assembly based on MSVR

Location layout of aircraft assembly is an important factor affecting product quality. Most of the existing re-searches use the combination of finite element analysis and intelligent algorithm to optimize the location layout, which are limited by numerical simulation accuracy and the selection and improvement of intelligent algorithms. At present, the analysis and decision-making technology based on field data is gradually applied in aircraft manufacturing. Based on the perception data of intelligent assembly unit of aircraft parts, a regression model of multi-input and multi-output support vector machine with Gauss kernel function as radial basis function is established, and the hyperparameters of the model are optimized by hybrid particle swarm optimization genetic algorithm (PSO-GA). GA-MSVR, PSO-MSVR and PSOGA-MSVR model are constructed respectively, and their results show that PSOGA-MSVR model has the best performance. Finally, the design of the aircraft wing location layout is taken as an example to verify the effectiveness of the method.     

基于遗传算法的定位布局优化新方法

在夹具设计过程中,建立了一种定位元件布局确定的新方法.该方法基于模糊评判,考虑候选表面特征类型、表面面积、位置公差等影响因素,确定定位参考面和定位点的数量.以定位误差最小为优化目标通过遗传算法确定定位点的具体位置.最后,通过实例验证该方法优于检验设计,并且能有效提高定性精度.     

支持工艺设计的制造知识类型及层次模型

针对工艺设计人员对大量制造知识的需求问题,分析了制造知识与工艺设计的关系,按照对工艺设计的支持作用,将制造知识分为制造资源类、制造对象类和制造过程类三大类别,建立了包括零件层、属性层和数据库层的制造知识结构层次模型,以制造设备为例,采用IDEF1X方法建立了支持工艺设计的制造知识表达模型.     

基于精益生产的门框转包项目布局与设计

精益是一种管理理念,公司自2003年引入精益理念以来,一直将精益作为贯穿所有工作的基础。重点描述了公司在接入新的门框转包项目后,按照精益生产的要求,合理规划、布局生产线,并在设计生产线的基础上,利用了现状表、时间观察表等精益工具,对现场进行了局部的重点管理布局和整体管理改进,为产品服务,为生产服务。通过U型生产线布置,对工装型架进行改造,对现场管理进行创新改革,实现无纸化、零件和材料配送,用信息流拉动生产等方式,达到了优化布局的精益效果。     

基于最小不可识别损伤模型的传感器优化布置

提出了一种以不可识别损伤最小为目标的传感器优化布置方法。该方法在某种损伤情况下,建立结构的损伤模型,得到任意传感器潜在位置处的预测效应值,将使不可识别损伤模型数目减少到最小的布设方案做为最优方案。考虑到在求解最小不可识别损伤模型的个数的过程中计算量巨大,针对最小不可识别损伤模型个数的求解,编制了相应的优化算法。算例分析验证了此方法原理明确,操作简单,实用性较强。     

基于AutoCAD三维几何图形下的压力铸造网格剖分技术研究

选择AutoCAD软件作为前处理平台，实现压铸件三维实体造型，采用STL文件格式作为数据交换接口,根据“虚实”原理进行网格剖分，此方法为进行基于三维的压力铸造CAD／CAM的研究起到了积极的作用。     

基于面向对象技术的典型工艺知识库系统

建立了多层次的典型工艺结构,充分利用相似特征具有相似工艺的理论;研究了工艺查询、工艺评价和工艺设计等应用子系统的功能结构,开发了面向对象的典型工艺知识库系统。     

Development of theoretical approaches to the control of a water-treatment system

The Advanced Life Support/NASA Specialized Center of Research and Training (ALS/NSCORT) focuses on research and development of technologies to support human habitation during space missions. This research was done as part of an effort to maintain crewmembers’ water supply in a closed life-support system. The water subsystem was the primary focus of this study because water is one of the most expensive and important resources for human survival.     

A review of chatter vibration research in milling

Chatter is a self-excited vibration of parts in machining systems. It is widely present across a range of cutting processes, and has an impact upon both efficiency and quality in production processing. A great deal of research has been dedicated to the development of technologies that are able to predict and detect chatter. The purpose of these technologies is to facilitate the avoidance of chatter during cutting processes, which leads to better surface precision, higher productivity, and longer tool life. This paper summarizes the current state of the art in research regarding the problems of how to arrive at stable chatter prediction, chatter identification, and chatter control/suppression, with a focus on milling processes. Particular focus is placed on the theoretical relationship between cutting chatter and process damping, tool runout, and gyroscopic effect, as well as the importance of this for chatter prediction. The paper concludes with some reflections regarding possible directions for future research in this field.