In the programming of five-axis machining, computer aided manufacturing system manufacture usually uses lines instead of curves while surface machining. A large number of micro G01 straight line segments are used to machine surface, sharp creases will appear on surface of workpieces with large radius of curvature, which results in bad surface machining quality of workpieces. In order to improve the surface quality of workpieces machined by five-axis CNC machining system, a micro-line smooth interpolation algorithm for five-axis CNC machining is presented. In view of the dimensional difference of cutter axis vectors, our algorithm identifies discontinuous and continuous micro-line blocks of cutter axis vectors machining regions through the length of linearity axis, the angular variation of rotation axis and the intersection angle of linearity axis between adjacent command points. For the discontinuous micro-line blocks of machining regions, direct interpolation is conducted to guarantee the processing precision based on original lines and the rotation axis. For the continuous micro-line blocks of machining regions, get node parameters using five dimensions variables, least square method is used to correct command points in an allowed error range; Second-order tangent vectors of corrected command points are calculated by using four continuous corrected command points, cubic spline curves with continuity of second order are obtained according to corrected command points, node parameters and second-order tangent vectors; Real-time interpolation calculation is conducted on the second order smooth curves, machine tool is controlled to five-axis machining. Experimental results demonstrate that fitted path by smooth interpolation of micro lines in five-axis CNC machining is more close to the original surface model, the surface quality of smoothing pieces is better than the non-smoothing, our algorithm can improve the free curved surface quality of five-axis.
ZHAO Jianhua
,
ZHU Bei
,
LIU Fang
,
TAN Yundong
,
FAN Liuqun
,
GU Xianjie
,
HUANG Wei
. Smooth Interpolation of Short Lines in Five-axis CNC Machining[J]. Journal of Mechanical Engineering, 2016
, 52(12)
: 1
-8
.
DOI: 10.3901/JME.2016.12.001
[1] 周波,赵吉宾,刘伟军. 复杂曲面五轴数控加工刀轴矢量优化方法研究[J]. 机械工程学报,2013,49(7)：184-192.
ZHOU Bo,ZHAO Jibin,LIU Weijun. Method study on optimization of tool axis vector for complex surface of 5-Axis CNC[J]. Journal of Mechanical Engineering,2013,49(7)：184-192.
[2] 樊文刚,叶佩青. 复杂曲面五轴端铣加工刀具轨迹规划研究进展[J]. 机械工程学报,2015,51(15)：168-182.
FAN Wengang,YE Peiqing. Research progress in tool path planning for five-axis end milling machining of sculptured surfaces[J]. Journal of Mechanical Engineering,2015,51(15)：168-182.
[3] 耿聪,于东,张函. 五轴联动刀轴矢量平滑插补算法[J]. 机械工程学报,2013,49(3)：180-185.
GENG Cong,YU Dong,ZHANG Han. Tool orientation smooth interpolation algorithm for five-axis CNC machining[J]. Journal of Mechanical Engineering,2013,49(3)：180-185.
[4] 施群,游清宁,黄宇亮,等. 高速高精度曲线重构与递推插补研究[J]. 机械工程学报,2010,46(3)：193-198.
SHI Qun,YOU Qingning,HUANG Yuliang,et al. Research on reconstruction and recursion interpolation of curve with high-speed and high-precision[J]. Journal of Mechanical Engineering, 2010,46(3)：193-198.
[5] FANUC. FANUC Series 30i/31i/32i-MODEL A [EB/OL]. [2009-09-06]. http：//www.fanuc.co.jp/enproduct/cata log/ pdf/ FS0i-D(E)_v02_s.pdf.
[6] SIEMENS. SINUMERIK 840D/FM-NC programming：Mould machining[EB/OL]. [2009-09-01]. http：//www. auto-mation.siemens.com/mc/mediadb/46d00625-4f4e-4e61-98db-e8902b0e3cf5/TOC_pl_0909_en.pdf.
[7] ZHAO H,ZHU L,DING H. A real-time look-ahead interpolation methodology with curvature-continuous B-spline transition scheme for CNC machining of short line segments[J]. International Journal of Machine Tools and Manufacture,2013(65)：88-98.
[8] GASSARA B,BAILI M,DESSEIN G,et al. Feed rate modeling in circular-circular interpolation discontinuity for high-speed milling[J]. The International Journal of Advanced Manufacturing Technology,2013(65)： 1619-1634.
[9] TSAI M,NIEN H,YAU H. Development of a real-time look-ahead interpolation methodology with spline-fitting technique for high-speed machining[J]. The International Journal of Advanced Manufacturing Technology,2010,47(5-8)：621-638.
[10] 张晓辉,于东,洪海涛,等. 数控加工中的平滑压缩插补算法研究[J]. 机械工程学报,2011,47(5)：156-162.
ZHANG Xiaohui,YU Dong,HONG Haitao,et al. Research on smooth compression interpolation algorithm in CNC machining[J]. Journal of Mechanical Engineering, 2011,47(5)：156-162.
[11] CONG G,DONG Y,LIAOMO Z,et al. A tool path correction and compression algorithm for five-axis CNC machining[J]. Journal of Systems Science & Complexity, 2013,26(5)：799-816.
[12] 赵世强,于东,张晓辉,等. 适用于五轴数控加工的平滑插补算法的研究[J]. 中国机械工程,2012,23(19)：2337-2342.
ZHAO Shiqiang,YU Dong,ZHANG Xiaohui,et al. Research on smooth interpolation algorithm for five-axis CNC machining[J]. China Mechanical Engineering,2012,23(19)：2337-2342.
[13] 金育安,贺永,傅建中. NURBS及Hermite混合高速加工插补算法[J]. 浙江大学学报,2014,48(4)：641-648.
JIN Yuan,HE Yong,FU Jianzhong. NURBS-Hermite hybird interpolation for high-speed machining[J]. Journal of Zhejiang University,2014,48(4)：641-648.
[14] DONG H,CHEN B,CHEN Y,et al. An accurate NURBS curve interpolation algorithm with short spline interpolation capacity[J]. The International Journal of Advanced Manufacturing Technology,2012,63(9-12)：1257-1270.
[15] 施法中. 计算机辅助几何设计与非均匀有理B样条[M]. 北京：高等教育出版社,2001.
SHI Fazhong. Computer aided geometric design and non-uniform rational B-spline[M]. Beijing：Higher Education Press,2001.
[16] 李庆扬,王能超,易大义. 数值分析[M]. 北京：清华大学出版社,2001.
LI Qingyang,WANG Nengchao,YI Dayi. Numerical analysis[M]. Beijing：Tsinghua University Press,2001.
