基于资源的汽车白车身装配CAPP及仿真系统的研究与实现

【作者】 黄洁；

【导师】 杜平安；

【作者基本信息】 电子科技大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 为提高汽车白车身装配质量和效率,有效管理制造资源,对计算机辅助工艺设计技术进行了研究。文章按照实际生产阶段顺序,将内容分为装配序列规划、装配工艺设计和装配过程仿真三部分。对基于配合约束的装配序列规划的遗传算法、制造资源建模、交互式图形化工艺设计、工艺设计与系统仿真的数据复用、装配车间物流仿真、装配线作业平衡优化、装配过程仿真等理论和方法进行了深入的研究。在理论研究基础上,采用面向对象技术和VC++6.0、SQL Server数据库工具,设计了一个集工艺设计、生产仿真和数据管理为一体的协同系统。系统实现了可视化、模块化、智能化的工艺设计,工艺数据的管理、查询、编辑和生产指导书的自动生成,并提供了基于权限分配的用户管理。已完成的主要工作有:(1)提出将工艺设计过程与制造系统仿真无缝集成,用工艺设计的结果驱动仿真系统,用仿真结果指导修改工艺设计。(2)定义了装配配合约束的类型和特征尺寸,借助“特征标签”、可装配度函数和遗传算法实现了在装配约束条件下,装配序列规划的寻优。(3)采用直接面向制造过程的工艺设计思想,直接利用基于制造资源的装配活动单元进行工艺设计,便于对设计结果进行修改和保存。(4)创造性地使用图形化界面进行交互式工艺设计,将制造数据信息封装在简明的图形之中,方便设计和操作。(5)建立了装配车间布局的数学模型,在虚拟车间中实现了装配过程物流仿真、布局面积和物流路径长度的计算。(6)提出了一种基于作业约束的求解装配线平衡问题的遗传算法,改进了算法的编码方法,添加了装配作业之间的约束条件。(7)在考虑有限缓冲区和随机发生故障对装配线性能影响的基础上,对装配生产过程进行了仿真,将得到的设备利用率、缓冲区利用率、工位工作时间和工位甘特图等统计数据以图形显示。(8)引入用户自建资源数据库的思想,使本文研究的工艺设计系统不仅适用于汽车白车身装配环境,也可广泛应用在其它生产制造行业和领域,具有极强的通用性。在系统开发的过程中,无先例可循,上述大多设计思想均是自主设计。实践证明,该系统能有效地管理车身装配中的产品数据,提高装配效率,帮助工艺人员对装配过程进行直观的评估和验证,并可应用于其它多种行业和领域。更多还原

【Abstract】 To improve the quality and efficiency of automotive body assembly and manage the manufacturing resource, researches on computer aid process planning are conducted in the paper. The paper is divided into three parts according to the actual manufacturing sequence, the assembly sequences planning, the assembly process planning and the production simulation. Sub research topics include the genetic algorithm for assembly sequences planning based on assembly constraint, modeling of the manufacturing resource, graphical and interactive process planning, the data-sharing between process planning and system simulation, material flow simulation in workshop, assembly line balancing and the production simulation.A integrated system for process planning, production simulation and data management is developed by Object-oriented programming method with the support of VC++6.0 and SQL Sever. The conception of“Assembly Cell”which can make the process planning graphical, modular and intelligent is put forward in the paper. The inquiry and edit of the technical data and the automatically creation of production guide book is realized. In addition, user management based on the authority assignment is provided by the system.The work has been done are as follow:(1) The process planning and production simulation were connected smoothly. The production simulation was drived by the result of process planning and the process planning was redeployed according to the result of production simulation.(2) Defined the types of assembly constraint and characteristic dimension. The genetic algorithm aimed to find the most reasonable assembly sequence under assembly constrains was carried out based on the“feature mark”and assemblability function.(3) Process planning was done directly using the assembly cells which were based on the manufacturing resource. This design was much easier to modify and save than before.(4) Process planning was designed with a graphical user interface in a creative way. The manufacturing datas were packed in simple graphics. So there could be operated conveniently.(5) The assembly workshop model was created. The material flow simulation and computation of workshop area and path length were realized.(6) An improved genetic algorithm for assembly line balancing based on job constraint was proposed. In order to improve the searching performance, a new encoding method and job constraint were using in the algorithm.(7) Production simulation was implemented considering the limited buffer and random broken down of the equipments. The system could display the operating factor of work position and buffer, the working state of work position, the Gantt chart in the form of graphics and digital(8) Because the users could make the database by themselves, the system could be used not only in white car body assembly, but also be widely used in others fields.As there is no precedent for reference in the process of system design, many ideas and concepts are raised by ourselves. Proved by practice, this system could manage the product data in automotive body assembly, improve the efficiency of production and help users evaluate and validate the assembly process effectively. What’s more, it has application in many other industry and fields.更多还原