测量点云的数控加工轨迹规划研究

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题名	测量点云的数控加工轨迹规划研究
作者	金海洋
学位类别	硕士
答辩日期	2015-05-26
授予单位	中国科学院沈阳自动化研究所
授予地点	中国科学院沈阳自动化研究所
导师	赵吉宾
关键词	数控加工曲面重建轨迹规划环形轨迹
其他题名	Study On NC Tool Path Planning For Piont Cloud
学位专业	机械电子工程
中文摘要	如今测量技术的发展使得逆向工程成为可能，基于测量点云的数控加工还原出原始零件模型在加工制造业正发挥着不可估量的作用。此外，客制化产品需求的增长也使得利用数控机床加工出手工设计模型的生产方式日益重要。而测量点云的数控加工轨迹规划是基于点云的数控加工过程中的重要环节，它是指以从待加工曲面测量得到的点云为研究对象，利用点云的数据信息生成数控机床的刀具运动轨迹的问题。本课题为了满足精加工的需求采用了先重建出参数曲面，再在参数曲面上做轨迹规划的思路，对这个问题进行了深入地研究。文中首先探讨了参数曲面重建的问题。目前比较主流的方法是用若干块参数曲面逼近或插值拟合出局部的曲面，再合并出整个曲面。这种方法的缺点是很难找到合理的点云分割方法，且合并曲面的过程也会产生误差。本文采用了先重采样出规则的空间点阵，再做整体拟合的思路。具体思路是首先做点云三角化处理，三角化后将三角网格调和映射到平面上，在平面上重采样并映射到空间得到规整点阵，最后整体拟合出曲面模型。整体思路实现过程中提出了鲁棒性较强的启发式点云局部三角化算法和基于测地距离投影的空间三角化的方法。本文另一个重要的研究内容是在参数曲面上规划出行形轨迹和环形轨迹。文中首先研究了常规的轨迹规划方法的优缺点。然后实现了曲面上的等参数法和等残留高度法的轨迹生成算法，找到了一种很好的等残留高度法的后处理算法。并提出了一种基于映射的环形轨迹规划方法。此方法首先利用映射方法对曲面的参数域做再参数化处理，将矩形参数域映射成环形参数域。然后在环形参数域上做环形轨迹规划。这有效地提高了算法时间上和空间上的效率。最后本课题利用ACIS/HOOPS函数库在Visual Studio集成开发环境下和同学们合力开发出了数控加工的仿真软件，本文中所研究的轨迹规划算法被成功应用到软件系统中的轨迹规划模块。现今此仿真软件已成功应用到实际生产中。文中主要介绍了软件的系统架构和运作流程以及轨迹规划模块的结构。
索取号	TG659/J67/2015
英文摘要	Nowadays, reverse engineer can be achieved because of the development of measurement technology. Metric point cloud based NC machining is playing a significant role in manufacturing industry for imitate an existed part. What’s more, the improvement of customized product’s requirement increases the importance of NC machining for the model designed by designer’s hands. And metric points based tool path planning is the key of this technology, which treats three-dimensional scattered points as the study, and achieves tool path according to these metric points. In order to work for the finishing machining, we use the following method: Firstly reconstruct the parametric surface according to the metric point cloud. After that we plan tool path on the parametric surface. This paper has a research on the methods for surface reconstruction at first. Among these methods, the mostly used way is divide-and-conquer, which means we should divide the point cloud before fitting surface, and lastly merge the whole surface. However, this method is difficult to decide how to divide these scattered points. What’s more, it would cause error during the procedure of merging the surfaces. On this paper, we fit the whole surface through a cloud of resampled ordered point. Specifically, at first we triangulate the scattered points; secondly, map the generated triangulation to the plane and resample ordered points on the plane; At last, fit the whole surface. On this research we propose a robust heuristic algorithm for locale triangulation and a geodesic based projection method for three-dimensional triangulation. Another important research is to plan the direction parallel tool path and contour parallel tool path on the parametric surface. At first, we have a research on the advantages and disadvantages of all kinds of tool path planning algorithm. We finish the tool path planning with iso-parametric and iso-scallop height methods. And find a good algorithm for the post-treatment of constant scallop height tool path planning. Last but not least, we proposed mapping based contour parallel tool path planning. This method firstly maps the rectangular parameter domain into a contour parameter domain. Then have a tool path plan on the contour parameter domain, which improves the algorithm’s efficiency. At last, with the help of my classmates I make use of ACIS/HOOPS and Visual Studio to develop the imitation software of the machining. This paper’s algorithms for tool path planning have been used on this software. Now this software has been successfully used on the actual part’s output. On this paper, mainly introduce the framework of this software, the procedure of its using and the structure of tool path planning part.
语种	中文
产权排序	1
页码	68页
内容类型	学位论文
源URL	[http://ir.sia.ac.cn/handle/173321/16760]
专题	沈阳自动化研究所_装备制造技术研究室
推荐引用方式 GB/T 7714	金海洋. 测量点云的数控加工轨迹规划研究[D]. 中国科学院沈阳自动化研究所. 中国科学院沈阳自动化研究所. 2015.