【作者】 赵华；

【导师】 李佳；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2009， 硕士

【摘要】 本文在总结前人关于排料问题的研究成果的基础上,根据海洋钻井平台工程的行业特点,对二维不规则零件的排料问题和切割问题展开研究,搭建了相应的自动排料及数控编程系统框架,并对排料问题深入研究,开发了系统的自动排料部分。论文首先对海洋钻井平台工程中的二维不规则零件特征进行分析,应用AutoCAD二次开发技术实现了图形数据获得、数据管理并设计了高效实用的零件操作算法。在此基础上,针对海洋钻井平台二维不规则零件的排料问题提出了一种高效实用的算法,即启发式搜索算法与遗传算法相结合的排料算法。首先根据行业特点定义合适的启发规则,利用启发式搜索算法对零件进行初次排料,形成初始排料方案。然后利用遗传算法对初始排料方案进行优化。初始排料方案作为遗传算法初始种群的一个母本,对其进行受迫变异产生一个相对优秀的初始种群,再进行遗传操作。为了充分发挥遗传算法的全局搜索的优势,同时又能得到较高的搜索效率,提出“染色体成长法”对染色体进行解码。把体现零件种类信息的染色体转化为实际待排零件的序列,再把这个零件实体序列通过启发式搜索空白区域的方法进行填充,把染色体的最大优势发挥出来。这样既充分利用了遗传算法的全局搜索能力,又利用启发式搜索算法大大提高了搜索效率。本文在科学的排料算法研究的基础上,根据人机交互的设计原则,在AutoCAD平台上开发出了与AutoCAD完全兼容并且简单易用的排料系统。最后总结了算法与系统的优缺点,对算法和系统的改进提出了一些建议。更多还原

【Abstract】 This paper summarizes the production of the former scholars about the nesting problem. Based on the characteristic of industry of Offshore Drilling Platform, this paper studies the the nesting problem and incising problem of the two-dimensional irregular parts, builds a system frame for the automatic nesting and numerical control programming ,and does a deep research about the nesting problem of the two-dimensional irregular parts, finishes the part of automatic nesting.Firstly, analysis about the characteristics of the parts used in Offshore Drilling Platform has been done. Then, this paper achieves the function of gaining and managing graphics’data, and also designs efficient methods of operating parts which have a high practicality. And based on those methods, this paper raised an efficient arithmetic to resole the nesting problem of the two-dimensional irregular parts used in Offshore Drilling Platform, which combines heuristic search and genetic algorithms (GA) to pack the parts by two phases. The initial result of the nesting has been formed by the heuristic search after heuristic rules have been defined depending on the characteristics of the special industry. The unperfected result produced in the first step is optimized by the genetic algorithms. In the genetic algorithms, the pollen parent is the result produced in the first step, and this pollen parent gives birth to the initial group by aberrance. At same time, the chromosomes don’t reflect the results of layout. And there is a process to decode the chromosome into nesting result, during which the chromosomes just like growing up. During the process, firstly, translate the chromosome which containing the information of the sorts into a array of the real parts waiting to layout; secondly, put those parts in that array into the block board by the heuristic search by which the predominance of the chromosome can be exerted at the completely. Through that, we don’t only use the genetic algorithms to achieve the full-scale search, but also gain a high effect by the heuristic search.Based on the scientific method and the principle of man-machine conversation, this paper exploits a handy nesting system, which can be compatible with AutoCAD completely. Summarize the advantage and disadvantage of the arithmetic and system, finally put forward suggestions to promote the arithmetic and system.更多还原