面向三维数字化制造的机加工艺设计与优化技术研究

发布时间：2018-08-01 19:15

【摘要】：三维数字化制造技术以三维建模仿真替代传统的物理样机试验,与传统制造技术相比,在提高产品质量和降低生产成本方面表现出了更大的技术优势,近年来受到工业界和学术界的广泛关注。然而,三维数字化制造技术的推广应用受传统基于二维工程图的工艺设计模式影响,目前存在业务和信息管理流程不统一、数据传递不一致等诸多问题。工艺设计过程过度依赖人工经验,设计结果的合理性难以得到有效保证。为了解决上述问题,本文针对机械加工(简称机加)工艺,探索了三维数字化工艺设计新模式,借鉴基于模型定义(Model Based Definition,MBD)技术思想和原理,构建了面向三维数字化制造的工艺设计与优化体系。重点研究了基于典型工序MBD模型的工艺路线决策与优化、基于模型定义的工序设计与优化和面向CAD/CAPP/CAM集成的虚拟加工环境优化配置等关键技术。论文主要研究内容如下:(1)构建了面向三维数字化制造的机加工艺设计模式与技术体系。针对当前三维数字化设计制造过程中存在的数据传递不一致的问题,提出工序MBD模型驱动的三维数字化机加工艺设计模式,将工序MBD模型作为信息传递的唯一载体,避免了二维工程图和三维模型的转换过程,保证了数据传递的一致性。构建了面向三维数字化制造的机加工艺设计体系结构,为后续理论及方法的研究提供了总体框架。(2)研究了基于典型工序MBD模型的工艺路线决策与优化方法。为了简化工艺路线推理过程,提出了基于典型工序MBD模型的工艺路线推理方法。通过特征与典型工序MBD模型匹配,减少了不必要的加工方法、机床和工装选择决策步骤,简化了工艺路线推理过程。研究了基于粗糙集理论的典型工序MBD模型优选方法,通过工艺知识的度量和距离计算,实现了工艺路线的优化,保证了工艺路线推理结果更具客观性、合理性。(3)研究了基于模型定义的工序设计与优化方法。为了消除过渡特征对工序几何建模准确性的影响,提出一种基于过渡特征简化的工序三维几何建模方法,通过重建过渡特征线段对过渡特征进行简化,消除了圆弧曲面对加工特征边界获取的干扰,保证了工序几何建模的准确性。研究了工序MBD模型组织管理方法,采用超变量几何相关性技术建立工序MBD模型几何变量关联关系,实现了工序模型自动更新,简化了工序更改过程。为保证工步安排的合理性,进一步研究了基于改进遗传算法的工步优化排序方法。以缩短加工辅助用时为优化目标,采用精英保留策略设计遗传算法步骤。该方法能够以较快的收敛速度获取全局最优解,得到加工辅助用时最少的加工工步序列。(4)研究了面向CAD/CAPP/CAM集成的虚拟加工环境优化配置方法。为了简化三维虚拟加工环境配置过程,提出了基于工序MBD模型的虚拟加工环境配置方法。通过模板调用的方式自动配置虚拟加工环境,简化了CAM阶段的工艺准备过程,提高了工艺设计效率。为了实现制造资源的合理利用,以机床模型作为研究对象,提出了基于加工能力元聚类的机床模型优化配置方法。采用区间数FCM聚类算法获取机床模型最优集合,降低了人工经验对机床选择过程的主观影响,保证了机床配置方案的合理性。(5)设计开发了三维数字化工艺设计与优化系统。基于UG/NX7.5平台设计开发了UG-CAPP原型系统,并通过TC系统和UG-CAPP系统的集成应用,实现了三维数字化工艺设计与优化。以飞机双面大框结构件的机加工艺设计实例,验证了本文所提方法和技术的有效性。
[Abstract]:Three dimensional digital manufacturing technology, replacing traditional physical prototype test with 3D modeling and simulation, shows greater technical advantage in improving product quality and reducing production cost compared with traditional manufacturing technology. In recent years, it has been widely concerned in industry and academia. However, the popularization and application of 3D digital manufacturing technology has been transmitted. On the basis of the process design model based on two-dimensional engineering drawing, there are many problems such as disunity of business and information management process and inconsistency of data transmission. The process of process design relies on artificial experience too much, and the rationality of design results is hard to be guaranteed. In order to solve the above problems, this paper is aimed at the process of machining (abbreviation). In this paper, a new model of 3D digital process design is explored, and a process design and optimization system for 3D digital manufacturing is constructed for reference based on Model Based Definition (MBD) technology. The process route decision and Optimization Based on the typical MBD model of the typical process and the process design based on the model definition are studied. The key technology of optimization and CAD/CAPP/CAM integration oriented virtual machining environment optimization configuration. The main contents of this paper are as follows: (1) the design mode and technical system of machine addition oriented to 3D digital manufacturing are constructed. In view of the problem of inconsistency of data transmission in the process of 3D digital design and manufacture, process MBD is proposed. The model driven three-dimensional digitized machine plus process design model takes the process MBD model as the only carrier of information transmission, avoids the conversion process of two-dimensional engineering drawing and 3D model, and ensures the consistency of data transfer. The structure of machine addition design architecture for 3D digital manufacturing is constructed for the follow-up theory and method. The overall framework is provided. (2) the process route decision and optimization method based on the typical process MBD model is studied. In order to simplify the process route reasoning process, a process route reasoning method based on the typical process MBD model is put forward. The unnecessary processing method, machine tool and tooling selection are reduced by matching the typical working procedure MBD model. The process route inference process is simplified. The optimization method of MBD model in typical process based on rough set theory is studied. The optimization of process route is realized through the measurement of process knowledge and distance calculation. The process route reasoning result is more objective and reasonable. (3) the process design and Optimization Based on the model definition are studied. In order to eliminate the influence of transition characteristics on the accuracy of process geometric modeling, a three-dimensional geometric modeling method based on the simplification of transition features is proposed, which simplifies the transition feature by reconstructing the transition feature line segment, eliminating the interference obtained by the arc curved facing the machining feature boundary, and ensuring the accuracy of the process geometric modeling. The method of organizing and managing the process MBD model is studied. The relationship between the geometric variables of the process MBD model is established by using the hypervariable geometric correlation technology. The process model is automatically updated and the process change process is simplified. In order to ensure the rationality of the work step arrangement, the optimization sorting method based on the improved genetic algorithm is further studied. The short processing auxiliary is used as the optimization target, using the elite reservation strategy to design the genetic algorithm step. This method can obtain the global optimal solution with the fast convergence speed, and get the least processing step sequence in the processing auxiliary use. (4) the optimization configuration method of virtual addition environment for CAD/CAPP/CAM integration is studied. In the process of processing environment configuration, a virtual machining environment configuration method based on process MBD model is put forward. The virtual machining environment is automatically configured through the template call, which simplifies the process preparation process in the CAM stage and improves the efficiency of the process design. In order to realize the rational utilization of the manufacturing resources, the machine tool model is proposed as the research object. The optimization configuration method of machine tool model based on processing capability element clustering. The interval number FCM clustering algorithm is used to obtain the optimal set of machine tool model, which reduces the subjective influence of artificial experience on machine tool selection process and ensures the rationality of the machine tool configuration scheme. (5) the design and optimization system of the three dimension word processing is designed and developed. Based on the flat method, the design and optimization system of the machine tool is designed and developed. The platform design and development of the UG-CAPP prototype system, and through the integrated application of TC system and UG-CAPP system, the three-dimensional digital process design and optimization are realized. An example of the aircraft double face large frame structural parts is designed to verify the effectiveness of the method and technology proposed in this paper.
【学位授予单位】：西北工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TH16

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