基于弧长参数的Akima刀位轨迹拟合算法研究

发布时间：2018-09-10 09:54

【摘要】：在数控加工中,通常用小线段表达刀位轨迹,往往会导致刀位点庞大且轨迹不平滑。基于Akima曲线具有光顺连接且端点连接处保证G1以上连续等特点,将刀位点拟合成Akima样条曲线,提出了基于弧长参数的保凸Akima拟合刀位轨迹算法。该算法分为刀位点搜索和拟合两个阶段:首先利用拟合刀位轨迹的误差测试(双弦误差测试和弦切误差测试)约束,获得该段的首末刀位点;然后在该段内根据首末刀位点计算切线矢量,用弧长信息对刀位点参数化,生成一段Akima样条。利用UG软件生成了内含75个刀位点的鞋底模型,通过MATLAB编程和仿真实验,设置不同测试阈值,对比了弧长参数化Akima曲线与节点参数化Akima曲线、NURBS曲线之间的拟合效果,验证了算法的有效性。
[Abstract]:In NC machining, the tool position locus is usually expressed by small line segments, which often leads to large tool loci and uneven path. Based on the characteristics of smooth connection of Akima curve and continuity of G1 at the end joint, the tool site is synthesized into Akima spline curve, and a convex preserving Akima tool path fitting algorithm based on arc length parameter is proposed. The algorithm is divided into two stages: firstly, the first and last tool locus of this section is obtained by using the error test (double chord error test and chord tangent error test) constraint of fitting tool locus. Then the tangent vector is calculated according to the first and last cutting site in the section, and the arc length information is used to parameterize the cutter site to generate a segment of Akima spline. The soles model with 75 tool sites was generated by using UG software. Through MATLAB programming and simulation experiments, different test thresholds were set, and the fitting results between the arc length parameterized Akima curve and the node parameterized Akima curve and Nurbs curve were compared. The validity of the algorithm is verified.
【作者单位】：湘潭大学复杂轨迹加工工艺及装备教育部工程中心;华中科技大学国家数控系统工程技术研究中心;
【基金】：国家自然科学基金资助项目(51375419,51575466,51575210) 湖南省自然科学联合基金资助项目(2017JJ4053) 湖南省教育厅创新平台资助项目(17K091)
【分类号】：TG659

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