面向航空发动机装配管理的动态表单系统研究

针对航空发动机装配生产中使用大量表格的特点,提出了动态表单解决方案,研究了各种表格数据的结构化存储技术,实现了装配过程的数字化管理。对基于表单的发动机装配流程进行建模,分析了表单的结构,建立表单的通用模型。使用面向对象技术,设计了表单系统的关键类,基于关系数据库设计了表单的结构化存储方案。设计了表单引擎,实现了表单数据的解析和结构化查询。最后结合发动机装配流程,应用该系统实现了装配过程的数字化管理。     

航空发动机低压涡轮数字化装配仿真

通过基于三维数字化模型的装配工艺仿真技术,实现基于航空发动机低压涡轮模型在可视化的数字环境中的装配路径规划、装配分析和装配仿真,以验证产品的可装配性及其工艺过程,从而能及时发现产品设计和工艺规划中的缺陷与错误,从而进行改进。民用航空发动机数字化装配仿真分析研究,为下阶段仿真技术研究的体系化与标准化建设奠定了基础。     

航空发动机教学实验系统的虚拟装配技术研究

航空发动机虚拟教学实验系统的建设是将VR(Virtual Reality)技术与实验相结合的一次综合性的实验探索与尝试.该系统是将虚拟装配及拆卸、模化实验、模型流场的动态显示及发动机试车等综合仿真实验系统,重点论述了教学实验系统开发中的虚拟装配技术,在对虚拟装配的研究现状分析和总结的基础上,对航空发动机虚拟装配的关键技术和虚拟装配系统的实现方法进行了分析和研究,包括基于数据手套的虚拟手操作、实时碰撞检测、装配路径和装配顺序规划等问题.最后还展示了利用航空发动机三维可视化虚拟装配系统完成虚拟装配操作的实例,并分析了虚拟装配系统与传统装配相比较的优势和特点.     

虚拟装配技术及其在航空发动机行业的应用

发动机的可靠性、寿命及主要性能参数在很大程度上取决于装配工艺水平和装配质量.作为航空发动机制造中的最终阶段,传统的发动机装配也是发生质量问题最多的阶段,由于在编制装配工艺初期,没有数字化装配验证的手段,在实际装配阶段,经常会发生零部件间的干涉或装配顺序不合理等现象,而且许多零部件制造阶段产生的质量隐患往往要等到装配阶段才能显现出来,因而导致航空发动机装配周期很长,返工率很高,而且装配质量不稳定,这些都严重制约着航空发动机行业的生产能力的提高.     

面向智能制造的在线通用虚拟装配系统

针对智能制造领域存在的虚拟装配系统通用性不足的问题,提出一种在线通用虚拟装配系统。该系统在传统虚拟装配方法的基础上研发了针对复杂层次化模型的通用装配算法,结合装配管理数据库自由规划装配序列,基于客户端网站实现在线虚拟装配,用户可自主上传三维模型数据并进行可视化装配逻辑设计,利用云服务器端的高计算性能和渲染性能降低客户端硬件要求,便于系统统一维护和更新,具有便捷性、灵活性、易推广的特点。以飞机、航空发动机、汽车发动机三种模型为例对系统的可行性进行检验,并且,以飞机虚拟装配为例,对系统的交互性能进行测试。实验结果表明,对于不同机械产品,系统具有通用性,其中,以飞机为例的130 s装配时段中,人机交互的每帧间隔时间最大为10.9 ms,最小为6.8 ms,平均间隔时间为8.79 ms,人机交互性能良好,能够满足用户交互需求。     

面向航空发动机的知识化制造系统拖期调度与自重构

针对某航空发动机装配线装配效率低、工人分配不合理等问题,建立面向航空发动机的知识化制造系统拖期调度和班组自重构优化模型.提出一种启发式算法,实现生产调度与班组配置的协同优化.在算法调度层中,针对航空发动机装配过程存在复杂约束这一特点,证明与产品拖期优化目标相关的工序排序性质,设计相应工序调整算法,给出工序在并行装配组上的初始分配方案和优化方案.在重构层,根据系统负载平衡的原则优化各装配班中装配组的数量.仿真实验结果表明了模型和所提出算法的有效性.     

PDM系统数字化装配工艺管理技术研究

数字化装配工艺设计管理系统,以产品研制为应用背景,基于企业统一的PDM平台,实现数字化、结构化装配工艺设计,可视化、流程化装配工艺数据管理。向上连接设计制造协同、工艺流水、工艺BOM系统,向下与ERP和MES系统紧密集成,形成企业信息化建设主体架构,支撑公司业务创新与发展。     

基于三维可视化技术的航空发动机试验舱设计

为了实现航空发动机试车舱的试车动画及简单的交互式控制,根据航空发动机试验舱的三视图,结合3ds Max软件建立发动机试车舱静态三维模型和制作发动机试车动画,然后将制作出的三维模型导入VC ++6.0平台去实现对模型的简单控制.通过试验,最终建立发动机试车舱模型,制作出发动机试车时的火焰气流效果,实现了鼠标对整个试车舱的...     

基于离散时间最优控制的航空发动机装配序列规划

为实现航空发动机维修差错的控制,采用基于优先约束关系的装配子网对发动机部件装配序列建模.在给定的装配评价准则下,将装配序列规划问题转化为最优变迁激发序列问题.引入离散时间的Pontryagin最小值原理(DTPMP),将极小化哈密顿函数这一全局优化的必要条件作为求解零部件装配序列的启发信息.为避免潜在死锁,给出了最优变迁激发序列算法.最后对最优装配序列规划算法的分析显示,该算法有多项式时间的复杂度.     

利用 WebGL 技术实现机房动态虚拟装配设计的可视化

本文设计并实现了一个面向机房的动态虚拟装配系统.该系统将传统的三维虚拟装配分解为二维装配和三维可视化两部分.在二维装配阶段,用户只需简单的交互操作就可完成机房的装配,配置结果记录在系统动态生成的配置文件中;在三维可视化阶段,系统根据配置文件可视化装配结果,实现虚拟装配.这种动态虚拟装配的架构有效提高了装配的效率,使装配更简捷、修改更容易.此外,该系统采用 WebGL 技术实现可视化,使得该系统的操作可全部在浏览器端完成,系统的发布和使用更加便捷.     

基于装配顺序的飞机装配容差信息建模

论文提出了基于装配顺序的装配容差信息建模方法,以装配仿真路径规划 的装配顺序为基础,提取装配体中各零件的特征约束关系及相关的关键特征,进而获取组成 环容差信息,建立装配容差信息模型。该模型考虑了装配顺序对装配误差累积过程的影响, 减少了人工容差信息建模繁琐的交互操作,提高了装配容差信息的建模质量。基于DELMIA 平台开发了飞机装配仿真系统。该系统已在工程上成功应用,提高了飞机装配仿真的效率, 减少了飞机实际装配生产中的出错率。     

An expert system for design for robotic assembly

In recent years, due to the various advantages associated with automation and robotics, much work has been done in developing robotic systems for assembly operations. Since part design plays a major role in assembly, this paper deals with the design of parts for ease of robotic assembly. Considerable knowledge is available in the form of design for robotic assembly rules. In addition, a large amount of data is required for decisions regarding suitability of parts for robotic assembly. The implementation of design for robotic assembly rules would be much easier with the help of an expert system, which would guide the designer toward choosing the design alternative that can best facilitate ease of assembly from a robotic point of view.To this end, a prototype expert system for design for robotic assembly is developed and presented in this paper. The expert system was implemented as a production system, which consists of rules and Object-Attribute-Value (O-A-V) triplets to represent domain knowledge. In order to best utilize the domain specific knowledge, a state space search-based inference mechanism was employed. The implementation of the prototype system is illustrated with examples.     

A complexity model for sequence planning in mixed-model assembly lines

Sequence planning is an important problem in assembly line design. It is to determine the order of assembly tasks to be performed sequentially. Significant research has been done to find good sequences based on various criteria, such as process time, investment cost, and product quality. This paper discusses the selection of optimal sequences based on complexity induced by product variety in mixed-model assembly line. The complexity was defined as operator choice complexity, which indirectly measures the human performance in making choices, such as selecting parts, tools, fixtures, and assembly procedures in a multi-product, multi-stage, manual assembly environment. The complexity measure and its model for assembly lines have been developed in an earlier paper by the authors. According to the complexity models developed, assembly sequence determines the directions in which complexity flows. Thus proper assembly sequence planning can reduce complexity. However, due to the difficulty of handling the directions of complexity flows in optimization, a transformed network flow model is formulated and solved based on dynamic programming. Methodologies developed in this paper extend the previous work on modeling complexity, and provide solution strategies for assembly sequence planning to minimize complexity.     

基于装配约束动态管理的虚拟拆卸

装配约束是虚拟拆卸环境下必须考虑的装配体的重要信息，提出虚拟拆卸过程中装配约束的动态管理机制，并实现了基于装配约束导航的虚拟拆卸。装配约束的动态管理包括虚拟环境下装配约束的获取、表达以及拆卸过程中装配约束的动态维护，即装配约束的动态解除和产生，文中用装配约束图表达零件间的装配约束，提出装配约束的间接解除方法，并实现了基于装配约束推理的零件可拆卸方向的推导。最后，通过一个简单装配体的拆卸实例，对文中方法进行了验证。     

Assembly operation process planning by mapping a virtual assembly simulation to real operation

Virtual assembly has been widely used in product development. However, virtual operation and actual operation are different in time and space, the simulation of interactive virtual assembly cannot support the assembly operation's process planning directly. In this paper, the solution for assembly operation's process planning is developed based on interactive virtual assembly. According to the solution, interactive assembly operation is used to obtain the actions of operation sequence. The actions are mapped into the data of a real operation action to obtain real operation actions. Then assembly operation cards can be obtained. To support the assembly operation actions obtained through virtual assembly simulation, a product assembly model is proposed. An operation semantic model is used to replace the geometric constraint model of assembly, which contains several ordered geometric constraints and some engineering restriction conditions. To test the solution and the models, one process planning example of an automobile engine is introduced. The results verified the feasibility and the effectiveness of the methods.     

Automatic generation of assembly dimension chain based on tolerance cell

In the process of generating assembly dimension chain automatically,there are many problems such as complex assembly relationship,variety of constraints of components and complex dimension and tolerance relations of components.These problems lead to many difficulties in search process and need lots of man-machine interaction.Because of these difficulties,this paper presents a method of automatic generation of assembly dimension chain based on tolerance cell.This method is realized through obtaining assembly tolerance cell and part tolerance cell first.These two types of tolerance cell are extracted and expressed in the form of linked list structure in computer further.Then assembly dimension chain is searched automatically based on obtained tolerance cell,and the correct assembly dimension chain is extracted finally.A system of generating assembly dimension chain automatically has been developed based on DELMIA and successfully deployed in aircraft assembly simulation in the engineering practice.     

数据驱动的汽车总装线建模与仿真技术研究

现代制造业的生产模式向柔性制造和客户化定制方向发展,为了提高制造系统的快速响应能力,实现快速仿真分析,提出基于数据驱动的建模与仿真方法,其具有建模周期短、模型可读性、可重用性较高的特点.利用IDEFIX建模方法建立模型的底层数据结构,基于Arena构建仿真模型生成器,利用已建好的数据模型提供的属性信息,自动生成目标系统...     

基于AFDX和ACE的大气数据系统设计

以某飞行器作为研制背景,对基于航空全双工交换式以太网（AFDX）和自适应通信环境（ACE）中间件的大气数据系统进行了设计,探索新一代航空数据传输网络和中间件在航空系统中的应用。介绍了AFDX和ACE结构体系。给出了大气数据系统的结构、大气数据的计算公式和计算方法,使用ACE框架对大气数据系统进行了设计,实现大气数据的采集、传输和相关参数的计算。     

Mechanical assembly planning using ant colony optimization

In mechanical assembly planning research, many intelligent methods have already been reported over the past two decades. However, those methods mainly focus on the optimal assembly solution search while another important problem, the generation of solution space, has received little attention. This paper proposes a new methodology for the assembly planning problem. On the basis of a disassembly information model which has been developed to represent all theoretical assembly/disassembly sequences, two decoupled problems, generating the solution space and searching for the best result, are integrated into one computation framework. In this framework, using an ant colony optimization algorithm, the solution space of disassembly plans can be generated synchronously during the search process for best solutions. Finally, the new method’s validity is verified by a case study.     

An experimental study on augmented reality assisted manual assembly with occluded components

Augmented Reality (AR) technology has increasingly been applied to facilitate manufacturing tasks such as training, maintenance, and safety management, in which manual assembly frequently occurs. Previously, studies confirmed the values of AR-based assembly systems, but few explored support of spatially restricted assembly where components are visually occluded from operator. In this regard, this research aims to develop new AR functions that assist manual assembly in such situations. The focus is on validating the effectiveness of various assistive information in AR, including assembly interface, operator’s hand movement, and operator held components. Subjective and objective measures are used to evaluate assembly experiments of different degrees of difficulty. Analyses of the experimental data reveal whether or not and how effectively each information offers guidance in occluded condition. In particular, a time reduction in more difficult assembly is realized by showing operator hand movement in AR. The hand model initially offers an operator a visual clue for quickly and roughly locating the assembly interface in a large unseen area, prior to precisely localizing in a smaller region guided by tactile sensing. However, the effectiveness of incorporating the held component is not evident, as positional deviation between real and virtual objects may reduce human’s hand-eye coordination. These findings not only provide preliminary design guidelines of AR assembly functions for occluded components but also demonstrates a novel yet practical application of AR technology in smart manufacturing.