摘要
针对五轴线性路径加工轨迹在拐角处切向向量不连续导致加工效率低和运动不平稳等问题,文章提出一种基于双五次PH(Pythagorean-hodograph)曲线的五轴线性路径局部拐角光顺方法,其中一条PH曲线对刀尖点线性路径进行光顺,另一条PH曲线在单位球面上对刀轴矢量线性路径进行光顺;刀尖点和刀轴矢量近似误差通过一种几何方法解析约束,可实现五轴光顺轨迹近似误差可控;通过推导过渡曲线和原始线性轨迹在衔接点处刀轴矢量几何导数连续条件,使得光顺后刀具路径能达到G^(2)连续,并实现刀尖点和刀轴矢量PH曲线参数同步。仿真结果表明,该文提出的五轴线性路径局部拐角光顺方法可实现刀尖和刀轴矢量的近似误差严格控制,且刀尖和刀轴矢量通过拐角时连续变化;该方法提高了五轴局部拐角光顺计算效率,有利于集成到数控系统中并实现五轴线性路径加工轨迹在线光顺。
Aiming at the tangential discontinuity problem of linear path at the corner in five-axis machining,resulting in low machining efficiency and unstable motion,a method for the local corner smoothing of five-axis linear path based on the double quintic Pythagorean-hodograph(PH)curve is presented,in which one PH curve smooths the path of the tool tip point and the other PH curve smooths the tool orientation on the unit circle.The approximate errors of tool tip point and tool orientation are constrained by a geometric method,and the approximate errors of five-axis fairing trajectory are controllable.By deducing the continuous condition of the geometric derivative of the tool orientation at the connecting point between the transition curve and the remaining line,the parameters of two PH curves are synchronized.G^(2) continuity can be achieved in the tool path after smoothing.The simulation results show that the proposed five-axis path local corner smoothing method can strictly control the approximate errors of tool tip and tool orientation.After synchronization,the tool orientation changes continuously as it passes the corner.The computational efficiency of five-axis local corner smoothing is obviously improved,which is beneficial to integrating the algorithm into the numerical control system to realize the online smoothing of machining trajectory of five-axis linear path.
作者
陶廷江
韩江
姜阳
卢磊
黄晓勇
夏链
TAO Tingjiang;HAN Jiang;JIANG Yang;LU Lei;HUANG Xiaoyong;XIA Lian(School of Mechanical Engineering,Hefei University of Technology,Hefei 230009,China;Anhui Engineering Laboratory of Intelligent CNC Technology and Equipment,Hefei 230009,China)
出处
《合肥工业大学学报（自然科学版）》
CAS
北大核心
2022年第11期1460-1466,1534,共8页
Journal of Hefei University of Technology：Natural Science
基金
安徽省科技重大专项资助项目(S202003a05020087)。
关键词
五轴机床
线性路径
拐角光顺
PH曲线
参数同步
five-axis machine tool
linear path
corner smoothing
Pythagorean-hodograph(PH)curve
parameter synchronization
