【作者】 刘勇；

【导师】 肖人彬；

【作者基本信息】 华中科技大学 ， 机械设计及理论， 2005， 博士

【摘要】 当今信息时代,科学技术飞速发展,传统学科正在信息技术带动下焕发新的活力,各学科之间不断相互补充、交叉、渗透,从而使其理论研究范围和应用领域得到不断拓展。传统机械学在其研究对象、内容、理论与方法等方面也正经历着深刻变革,以使自身提高到与信息产业革命及其他学科发展相适应的层次,其中机械创新设计方法就是一个非常活跃的研究领域。本文借鉴国内外相关研究成果,以平面机构轨迹综合与创新设计理论为重点研究对象,将新型计算智能方法与创新设计理论引入其中,为平面机构轨迹综合与创新设计理论提供了一种新的研究途径。将人工免疫算法用于平面机构的直接和间接近似综合,对目前基于定量描述轨迹特征的机构轨迹综合方法进行了改进。在直接综合方法中采用了免疫网络多峰优化算法以解决优化算法普遍存在的解的相似性问题,该方法不仅具有良好的全局收敛性和鲁棒性,而且可以同时求得多个候选解; 在间接综合方法中则利用免疫计算方法在模式识别方面的优良特性,采用不同免疫计算方法模型对轨迹曲线进行聚类、分类和检索,提出了一种新的基于免疫计算的间接综合方法。借鉴颜氏机构创新设计方法学的创新策略,并将机构轨迹综合方法应用于机构创新设计,提出了基于轨迹特征的平面机构创新设计方法。随后对其重要支撑技术机构同构判定方法和机构运动链草图的自动绘制方法进行了研究:对机构同构判定问题,首先将其转化为可降次的旅行商问题,然后采用蚂蚁算法和免疫计算方法进行了求解; 机构运动链草图的自动绘制本质上可视为运动链图的基本回路的排列问题,通过引入图论方法对其基本回路进行生成与排序,提出了一种基于回路配置的机构运动链草图自动绘制方法。此外,本文还对基于定性描述轨迹特征的机械运动方案设计方法进行了研究,提出了机械运动方案设计的多粒度共进化功能推理方法,该方法采用分类功能来描述机构单元及机械系统的运动特征信息,将机构单元和机械系统都看成运动功能变换函数,通过多粒度功能推理来生成机械运动变换单元的串联组合方案。基于上述理论方法研究成果,研制了计算机辅助机构轨迹创新设计原型系统,并通过织布机开口机构设计实例验证了其可行性和有效性。更多还原

【Abstract】 In the information era with rapid development of science and technology, new vital force is being brought to traditional subjects by information technology, different subjects keep on supplementing, crossing over and infiltrating mutually, making their scopes of theoretical research and fields of application expanded continuously. In order to keep up with the revolution in information industry and the development of other subjects, traditional mechanics is going through profound changes in many aspects like research objects, contents, theories and methods, among which the Mechanical Creative Design (MCD) is a fairly active field. Using the relevant theoretical research achievements for reference, the path synthesis and creative design theory of planar mechanism is deeply researched in this dissertation, in which new methods of computational intelligence and creative design theory are introduced and a new approach to the theoretical research on path synthesis and creative design of planar mechanism is presented. By introducing Artificial Immune System (AIS) algorithms into the path synthesis of planar mechanism, the current direct synthesis methods and indirect synthesis ones are improved. In the former one, revised artificial immune network algorithm (ai-Net) for multimodal optimization is adopted to solve the problem of the similarity between candidate solutions, which is ubiquitous in current optimization methods. By means of the new method with good global convergence and robustness, a large number of candidate solutions with large deversity can be obtained; In the latter one, the excellent performance of immune-computing algorithms in pattern recognition is used to develop a new indirect path synthesis framework based on immune-computing, in which several different algorithms and models are applied to the clustering, classification and retrieval of path curves. Referring the creative strategy of Yan’s mechanism creative design method and applying the path synthesis methods mentioned above to mechanism design, a path-feature based planar mechanism creative design method is proposed. Furthermore, two important supporting technologies, viz. the isomorphic identification and the automatic sketching methods for mechanism kinematic chain, are discussed in detail. The former one can be transformed into a degree-reducible Traveling Salesman Problem (TSP) firstly, and then ant algorithm and immune algorithm are adopted to solve it easily. The latter one, which can be seen as the arrangement problem of the basic loops in the graph of mechanism kinematic chain in essence, can be solved by a new approach to automatic sketching of mechanism kinematic chain presented, in which graph theory is introduced to generate the basic loops and their proper order. In addition, how to generate mechanical kinematic scheme according to qualitatively described path features is also studied in this dissertation. In the new approach proposed to kinematic scheme generation based on multi-granularity co-evolutionary function reasoning, classified functions are used to describe the kinematic characters of mechanical units, each mechanism and mechanical system is treated as a motion-transforming function, ground on which series-connected mechanical kinematic schemes are generated by means of function reasoning method. Using object-oriented programming language, a prototype system for computer-aided mechanism path creative design is developed, by means of which the design of the shedding mechanism of simple loom is successfully accomplished. The case study indicates that the proposed methods are feasible and effective.更多还原