优化五轴联动非线性误差的刀具姿态控制方法  

A Tool Posture Control Method for Optimizing Nonlinear Error of Five-axis CNC Machining

作　　者：周永洪 郭灿彬[2] 李志强 Zhou Yonghong;Guo Canbin;Li Zhiqiang(Zhongshan MLTOR CNC Technology Co.,Ltd.,Zhongshan,Guangdong 528436,China;Guangdong Mechanical&Electrical Polytechnic,Guangzhou 510550,China)

机构地区：[1]中山迈雷特数控技术有限公司,广东中山528436 [2]广东机电职业技术学院,广州510550

出　　处：《机电工程技术》2024年第12期115-118,共4页Mechanical & Electrical Engineering Technology

基　　金：中山市重大科技专项项目(2022A1019)。

摘　　要：五轴数控机床运动轴的非线性运动导致五轴联动产生非线性误差。为了减小运动轴速度和加减速突跳,分析认为五轴联动线性插补不足以控制非线性误差,在此基础上提出刀具姿态控制的刀轴矢量实时插补方法。首先建立刀轴矢量局部旋转坐标系,构建刀具长度补偿矢量平面,确保已插补的刀轴矢量夹角与刀具长度补偿矢量呈线性关系,然后实现具备刀具姿态控制的旋转刀具中心点(Rotation Tool Center Point,RTCP)功能,计算非线性误差。仿真验证未开启RTCP、采用线性插补RTCP和刀具姿态控制的RTCP三种算法的插补轨迹,并将RTCP算法集成进数控系统里。以典型叶轮零件在AC双转台的五轴联动数控机床上进行加工,检测并对比3种插补算法在同一段工件曲面的加工误差值。相比未开启RTCP功能的插补算法,采用刀具姿态控制优化的RTCP算法加工误差减低了59%,加工精度提升效果显著。加工表面振纹、过切或欠切刀痕明显减少,刀纹光顺平滑,提高了表面光洁度。仿真和实际加工结果验证了刀具姿态控制的RTCP算法的有效性,可以工程化应用在产品中。The nonlinear motion of five-axis CNC machine tool leads to the nonlinear error.To reduce the velocity of the motion axis and the acceleration and deceleration jump,a tool axis vector real-time interpolation method for posture control is proposed,based on the research indication that linear interpolation is not enough to control nonlinear error in five-axis CNC machine.Firstly,the local rotation coordinate system of the tool axis vector is established,and the tool length compensation vector plane is constructed to ensure the linear relationship between the interpolated tool axis vector and the tool length compensation vector,and the rotation tool center point(RTCP)function with tool posture control is realized to calculate the nonlinear error.Simulations are carried out to verify the interpolation trajectory without RTCP,with linear interpolation RTCP and with tool posture control RTCP,and the RTCP algorithm is integrated into the CNC.The typical impeller parts ar machined on a five-axis CNC machine tool with AC double turntable,and the machining errors of three interpolation algorithms on the same workpiece surface are tested and compared.Compared with the interpolation algorithm without RTCP function,the machining error of RTCP algorithm optimized by tool posture control is reduced by 59%,and the machining accuracy is improved significantly.The surface vibration,over-cut or under-cut marks are significantly reduced,and the tool lines are smooth,improving the surface finish.The effectiveness of RTCP algorithm for tool posture control is verified by simulation and actual machining,and it can be applied in engineering products.

关 键 词：五轴联动加工 旋转刀具中心点 非线性误差 刀具姿态 

分 类 号：TG659[金属学及工艺—金属切削加工及机床]