【作者】 魏巍；

【导师】 郭晨；

【作者基本信息】 大连海事大学 ， 交通信息工程及控制， 2013， 博士

【摘要】 虚拟装配基于虚拟现实技术,在虚拟空间中构建产品的虚拟样机,使操作者身临其境的对产品设计的合理性和规范性、装配的可行性和难易度等因素开展可感知的验证研究。这对提高产品的研发速度,降低装配测试和培训成本,具有重要意义。然而,当前大多虚拟装配系统中,缺少公差等工程语义信息和装配规划辅助信息,造成系统普遍存在“仿而不真”和“装配无序”的现象,无法大规模推广实用。本文针对虚拟装配中的关键技术进行研究,并以某型号船用发动机为应用背景,仿真验证了所提的各项研究内容。研究带公差信息的零部件模型构建与公差信息可视化的方法。在传统零部件模型层次结构基础上,提出了公差信息层和工程辅助信息层结构定义,给出了模型各层次间信息的提取和映射方法。论述了零部件静态公差和动态公差的表述方式和应用范围,给出了静态公差与零部件的随动变换计算方法。研究带公差信息的零部件模型问的碰撞检测方法。提出了基于体分解的空间层次包围体表达方法,给出了压缩包围体冗余空间的算法。结合空间剖分技术,对装配局部空间进行剖分遍历,快速检测发生包围盒重叠区域。给出碰撞穿透深度的计算方法,依据此深度值与零部件公差范围进行比对,从而产生不同的碰撞响应策略。研究了零部件模型约束定位和多约束动态管理的方法。给出了模型间约束与几何元素的对应关系,约束几何元素间的距离及角度计算方法,约束识别的准则,及自由度归约与冗余约束检测的方法。给出了三类复合约束的定位方法,提出了约束动态管理的方法。研究了智能装配序列规划与装配仿真相结合的方法。提出了基于蚁群和遗传混合算法求解序列规划的方法。采用最佳融合策略,动态的调度两种算法的执行。提出了综合装配成本的概念,在计算中将装配中的工具变更,方向改变以及自定义装配因素考虑在内。给出了最优序列与装配仿真系统相结合的方法,将仿真装配中产生的问题作为装配准则,反馈给寻优算法,对其后续计算产生影响。更多还原

【Abstract】 Virtual assembly, based on virtual reality technology, could make the operator carry on the perceived verification research diametrically aimed at the the rationality and specification of the product design, and feasibility and ease of assembly and other factors by building virtual prototypes of products in an immersive virtual environment. It has the important significance to improve product development speed, lower assembly testing and training costs. At present, however, there are no engineering semantic information such as tolerance and assembly planning auxiliary information in most virtual assembly system, which results in the phenomenon of’like but do not really" and’assembly disorder’existing ubiquitously and the system could not be large-scale promotion and practical application. In this paper, the key technologies of virtual assembly are studied and various study contents proposed are simulated and tested based on application background of certain marine engine.The construction method of part model with tolerance information and the visualization method of tolerances information have been studied. The layers of tolerance and engineering auxiliary information are proposed based on traditional layer structure of part model and the methods of extracting information and establishing map relationship aimed at each layer are elaborated. The expression mode and application scope of static and dynamic tolerance are discussed and the follower transform calculation method of the static tolerance and parts is given. The collision detection method of part model with tolerance information is discussed. The expression method of the space hierarchical bounding volume based on the volume decomposition is proposed and redundant space compressing algorithm of the bounding volume is demonstrated. The overlap region of bounding boxes is detected rapidly by traversing assembly local space partition cell which is divided by the technology of space subdivision. The method of calculating collision penetration depth is provided and according to comparing this depth value with the tolerance range of the part, different collision response strategies are obtained. The part positioning method based on constraint and multi-constraint dynamic management approach are studied. The correspondence relationship between the constraint and geometrical element of part, the distance and angel calculation method between geometric elements constrained, the criteria of constraint recognition, and the methods of degree of freedom reduction and detecting the redundant constraint are elaborated. The positioning methods of three kinds of composite constraints are explained and the dynamic management approach of constraint is proposed. The combination method of intelligent assembly sequence planning and assembly simulation is studied. The hybrid algorithm based on ant colony and genetic algorithms is proposed to solve the assembly sequence planning. The ant colony and generatic algorithms are scheduled dynamically by the best algorithm fusion strategy. The concept of integrated assembly costs is proposed and the changes of the tool and the direction, and some custom assembly factors are taken into account in the calculation of integrated assembly costs.The method of combination between optimal sequence and assembly simulation system is illustrated and the problems generated in the assembly simulation could be as assembly criterion to feedback to the optimizing algorithm for influencing the follow-up calculation.更多还原